ri\lf)fjlfffnf!Jf1'GJ ~ 10 0·(2008 ~) pp. 25 -37© 2008 ~ B/fi:~IHH~tu!f~"OR" at the Semantic-Pragmatic Interface

Xinren Chen
Nanjing Un iversity

Tllis article proposes an operational and expl anatory account of how the "inclusive" account of "or"holds as agai nst the "exclusive" and "ambiguous" views. 1t is argued that "or", owing to its inclusiveness, is semantically underspecified, leaving it unclear whether j ust one or more of the items it conjoins
is intended given the truth of the entire statement. Such semantic underspecification requires pragmatic strengthe1ling in commmlication. Operationally, the identification of some incompatibility between or
among the alternatives in accordance with the contextual info rmation involved indexes the solely exclusive interpretation of "or". This study also sheds light on the interpretation of other usages of "or".
Keywords: or; and; disjunction; implicature

1.

.·1

.....,.;.,

Introduction

An ideal language, for purposes of accuracy and simplicity, would work supposedly
on a one-to-one mapping basis at all levels. Specifically, each word has one and only one
meaning and usage. Likewise, each sentence has just one single meaning corresponding
to just one context. Unfortunately, or rather fortunately, natural languages do not workthat way. After all, sheer simplicity does not mean economy, which binds human lingui stic behavior no less strongly (Zipf 1949). As a consequence, words of natural languages are in large measure polysemous, which may yield ambiguity and subtlety alike,lexical or sentential. "Or", the lexical item under study, provides an example of the issue.
There is a further complication. Ordinary language is adopted, often underspecified,
to characterize language itself. This leads to doubt whether the logical symbols like &and V are distinct from their natural counterparts ("and" and "or" respectively). Afterelaborate reasoning, Glice (1975) successfully defends the view that they do mean thesame, pointing out that the apparent differences in between are attributable to the phenomenon of implying. In this paper, rather than focussing on "and", we would like toaddress the dispute over "or" that involves tlu·ee different accounts. 1 While subscribing

1

It is necessary to distinguish between "account" and "view" fro m "reading" and "interpretation"
he re. By "accou nt" and "view", we refer to the general understanding of the lexical item ("or"). By" reading" and "interpretation", we refer to the specific message that "or" conveys in the given context.
25

26

to the overwhelmingly favored "inclusive" v1ew, this article attempts an explanatory
account of how this inclusive account holds as against the "exclusive" and "ambiguous"
views. We shall argue that "or", owing to its inclusiveness, is essentially underspecified
in that its semantic property leaves it unclear whether just one or more of the items it conjoins is intended given the truth of the entire statement. Therefore, such semantic underspecification requires pragmatic strengthening in communication. Unlike others, we shallprovide a mechanism for identifying the exclusive reading of "or" in various sorts of situations and an account of how thjs works. We shall contend that the respect for the facewants and interest needs of the hearer underlies the speaker's effort of minimizing thehearer's effort or cost by resort to the <and, or> scale. In view of this, we shall claimthat the sole recourse to the Maxim of Quantity under the Cooperative Principle as documented in existing studies is not an adequate explanation. Rather, what is at work is theinterplay between the Cooperative Principle and the Politeness Principle (the Tact Maximin particular).

2.

The multiple usages of the ordinary "or"In ordinary English, "or" is used for a variety of meanings. Look at the following
examples:
(1)

(2)
·.1

John's birthday is in June or July.
To attract others, one often needs to have a good appearance or a good personality.

In (1), since John's birthday necessarily falls either in June or in July but not in both,the items listed with "or" do not appear to hold at the same time (for an explanation see
the next section) so that we might regard "or" as semantically exclusive; i.e. only one
alternative, but not both or all, of the series linked by "or" can be true. However, suchan account does not hold in (2), where one may attract others if he or she has both a good
appearance and a good personality. In other words, "or" seems to be inclusive, meaning"at least one of the disjuncts", which corresponds to the logical operator "or".
In fact, the English "or" is even more complicated in its ordinary use than has beenshown. The following examples lend themselves readily to none of the above analyses:

(3)
(4)

Some people suffer from acrophobia, or fear of great heights.
His school is two or three away miles from his home.

By "sense" and "usage" we refer to the lexical information included in the dictionary. Thus, "an exclusive reading or interpretation" is one possible kind of understanding of the word "or" in a specific context, which differs from "an exclusive account or view" that some scholars have proposed to characterize the nature of the word. The same distinction is also drawn between "an inclusive reading or interpretation" and "an inclusive account or view".

"OR" at the Semantic-Pragmatic Interface

(5)
(6)

27

Rain or shine, I'll go.
Stand still or you get killed.

In (3), "or" is used to indicate equivalence between expressions. In (4), "or" is used
to indicate approximation. In (5), "or" is used to expression concession. Finally, in (6),"or" is used to indicate a consequence from not doing the specified act. 2
We are going to address two major questions from the pragmatic perspective: first,
what is the basic meaning of "or"? Second, are the peripheral usages of "or" derived fromthis basic usage? If so, how?

3. An inclusive account of "or"·. II

As specified in classic logic, "or" is a disjunctive operator as opposed to "and" whichis conjunctive. The inclusive account of "or" stipulates that P, V P2 is true if at least oneof P, and P2 is true, false iff both P, and P2 are false. Thus, this account allows of two
situations wherein the logical relation obtains: in one condition, one and only one of P,
and P2 is true; in the other condition, more than one of P1 and P2 is true.
How about "or" in ordinary language? In the literature, two major views have been
put forward regarding its meaning: the exclusive account and the inclusive account.
Specifically, according to the former account, if P1 is a statement, P2 is a statement, thenP1 V P2 is true if either P, or P2 (but not both) is true; by contrast, according to the inclusive account, P, V P2 is true if at least one of P1 and P2 is true. 3
We may now ask: which of the two accounts of the natural English "or" is plausible? Look at the following example:(7)

Tom is in his office or at home.

If we assume the credibility of the speaker in (7), then the statement will be true ifJohn's birthday is in June or in July. Thus, we may apply both the exclusive and inclusive accounts of the logical "or" to the analysis of the natural "or" since they comply withthe truth condition requirements. In other words, in examples like (1) and (7), it is impossible to pinpoint which account is being assigned to the natural "or".
However, this inability to identify the true nature of the natural "or" vanishes when2

"Or", instead of having a single or dual meaning, is in fac t a word with multiple meanings to theextent that each meaning seems to require individual treatment. If we accept this to be true, there mightarise a fourth claim that "or" is homonymic for its distinct senses.
3
Analogously, if P1 , P2, ... Pn are all statements, then P1 V P2... V Pn is true if just any one of themis true in the former case; or tn1e if at least one of P 1, P2 , • . . P11 is true in the latter case. In terms oftruth value, the number of conditions under whlch P t V P2V P3, . .. V Pn holds corresponds to the partition of {P t, Pz, P3, ... PnJ, i.e., the sum of cases where any individual member or any combination of
two or more members holds.

28

we look at the following examples:(8)(9)

For booking information, call 3840684 or 3840687.
For the new post, a diploma in mathematics or computer science is a must.

In (8), given that the speaker is serious about making the notice, the caller will get
the booking information if he or she does call both telephone numbers provided, although
one single call will suffice. Similarly, in (9), an applicant should be regarded as satisfying the requirements of the post if he or she has both diplomas.
Cases like (8) and (9) strongly suggest the natural "or" is to be read as inclusive
rather than exclusive now that the inclusive account can explain all the four examples
while the exclusive account, if adopted, could only explain some cases and make false
predictions in other cases.
Thus, the univocally exclusive account suffers fundamental problems because it is
not descriptively adequate. As we shall see, the fact that "or" takes an exclusive interpretation in an overwhelming majority of contexts does not mean that it is semantically
exclusive. For this reason, Horn (1972) claims, from the pragmatic perspective, that theso-called exclusive disjunction is not a "favored selection as a lexical item because there
is a real pressure in language against independent lexicalization of notions made redundant by implicature" . In other words, if a linguistic form X regularly conveys in mostcontexts the implicature Y, there will tend not to be a lexicalization of Y. 4 No doubt, theuse of "or" falls into this category.
There is yet a third account of the natural English "or", i.e ., ambiguity account(Quine 1952; Strawson 1952; Geach 1959), to address here. It is clai med that natural language disjunction is ambiguous, with both inclusive and exclusive readings. On this view,a sentence containing "or" is ambiguous between an inclusive reading and an exclusive
reading. For instance, the sentence ( I Oa) can have two interpretations as represented by( lOb) and (toe):(10)

a. Tom can speak Chinese or English.
b. Tom can speak Chinese or Eng1ish (but not both).
c. Tom can speak Chinese or English (or both).

The advantage of this account is obvious: by recourse to both readings of "or", it can
simplif-y the issue: i.e. in some cases, "or" takes the inclusive interpretation and in others
it takes the exclusive reading. However, this view is open to challenge at least on the fol-

4
Gazdar and Pullum (1976) assume a stronger position that such lexicalization may never exist in
any natural language. They point out that even the aut in Latin is not really an exclusive disjunction,although it is often pragmatically used to highlight the stark contrast between alternatives. Gazdru·( 1977) deduces a linguistic uni versal: No language has an exclusive disjunction morpheme.

"OR" at the Semantic-Pragmatic Interface

29

lowing grou nd: how can " or" acquire and maintain two contradictory senses? 5 It seems
quite a rarity for an English word to possess such a semantic trait, if this is the case.
Before we exhaust all other possible approaches, we are reluctant to accept this extraordinary existence as plausible and possible. Indeed, McCawley (1973) suggests that "or"need not be treated as an ambiguous lexical item but may be assigned a conventional
meaning and the fact that it often implicates the exclusion would then be a conversational implicature generated on the basis of (among other things) the Maxim of Relation.

4.

Interpreting "or" in its context

If the natural "or" is understood as equivalent to the logical symbol V, we claim that
owing to its inclusiveness, it is essentially underspecified, for its semantic property leaves
it open whed1er just one alternative, or more, or all of the items it conjoins can be selected. In other words, once we adopt the inclusive account of "or", we are faced with thefollowing question: given the plausibili ty of the inclusive account of "or", how is its
meaning actually comprehended by the audience? Our answer is: the resolution of the
proble m can be sought on the pragmatic ground because the semantic underspecificationof "or" requires pragmatic strengthening in communication. We can depend on pragmatic
principles for the construal of the intended meaning of "or" in communicative contexts.
Now that the inclusive account assigns "or" the meaning of "at least one", the word
may theoretically communicate both "just one of the disjuncts" and "more than one of the
disjuncts". Then, it is our task to specify the conditions under which the former meaning is intended and those under which the latter is intended. Another question we needto answer is the following: given the two possible meanings of "or", why do we generally assign the first meaning to the word?
Let's take up the first question first. Our hypothesis is that "just one of the disjuncts"
is intended and allowed when only one proposition containing the disjunct can hold truein the possible world projected by the statement. This hypothesis seems to work on theexamples we have previously used for the exclusive account. For instance, in (1), only
the exclusive interpretation is pragmatically fe licitous because one's birthday cannot fallin two months. Similarly, in (7), one cannot be in office and at home at the same ti me(but possible in the exceptional context where the office and the home are one and thesame place).
However, on the inclusive account, in (11), Tom will not offend the speaker if be

5

On the ulterance level, however, we may use the same linguistic expression to mean opposite ideas.
For instance,
You are really clever!
Th is utterance can mean both that the person indexed by "you" is truly clever and that he or she is being
foolish depending on the context. In the latter case, we say an irony is being intended by the speaker.

30takes both an apple and a banana if he is hungry.
(11)Tom, take an apple or a banana if you feel hungry.

Look further at the following example :(12)

a. Bush or Kerry will be elected as president in November.
b. Bush or Kerry will be elected as senator.

( 12) requires more than common sense. The choice between the exclusive interpretationand the inclusive interpretation entails the knowledge of American political system.
Given the background information that the political system of the United States has it that
only one candidate from either the Democratic Party or the Republican Party (or an independent candidate) will finally become the president of the country, it is impossible totake an inclusive reading in ( 12a); rather, the background information forces the reader orhearer to understand that one, and only one, of the two candidates, Bush and Kerry, will
be elected president in November. However, in (12b), the inclusive interpretation is possible because the rule of the senate allows more than one senatorship. Clearly, in the possible world we can construct on the basis of our background knowledge about American
politics, the exclusive interpretation must be assumed in the former case while the inclusive reading is possible, though not necessarily intended, in the latter case.
From the above illustration, it is clear that it is the contextual or pragmatic factor,
rather than the meaning of "or" proper, that determines the pervasiveness of the exclusive
reading and the possibility of the inclusive reading.
Thus, fo r utterances with an exclusive reading for "or", it is their semantic content
plus pragmatic factors that lead to the kind of reading (for further support of this argument, see Barret and Stenner 1971). Also, the exclusive reading only represents anurunarked use of the ordinary term that is by definition inclusive in its semantic scope.
Given the right context, it is derivable from the inclusive account via pragmatic inference.
To generalize, we can use two tests to check when the exclusive reading is obligatory and when the inclusive reading is possible. One test, "but not both/all of them"applies to the former case and the other test, "or both/aU of them" applies to the lattercase.6 When we adopt the exclusive reading of an utterance wi th "or", we can make thederivable message explicit by adding "but not both/all of them" and yet it will soundinvalid if we add "or both/all of them". Contratily, when the inclusive reading is acceptable (but generall y not accepted), we can clarify our message by adding "or both/aU ofthem" but it would be inappropri ate practically or sociall y if we add "but not both/all ofthem". Let's prove the tests using the previous examples:

6

In terms of implicature, "or" with the exclusive reading conventionally implies "but not both (or allof lhem)" while "or" with the inclusive reading conventionally implies "or both (or all of them)". The
two tests are derived from the fact that implicatures are reinforceable and defeasible.

"OR" at the Semantic-Pragmatic Interface

31(12a') Bush or Kerry will be elected as president in November, but not both.
(12a") ?Bush or Kerry will be elected as president in November, or both. (which goesagainst the general practice)(12b') Bush or Kerry will be elected as senator in November, but not both.
(1 2b") Bush or Kerry will be elected as senator in November, or both.
Clearly, the utterance with "or" taking the inclusive interpretation (12b) survives bothof the tests. Whether the speaker intends to convey (12b') or (12b") by saying (12b)depends on the degree of confidence he has about the two candidates, although thechances are that the speaker connotes the former because he would otherwise use "and"instead of "or". Now let's check (11):( LL') Tom, take an apple or a banana if you feel hungry, or both .
(1 1") ?Tom, take an apple or a banana if you feel hungry, but not both.
Here, (11 ") fails to pass one of the two tests not because the exclusive interpretation
is not allowed but because it is not supposed to be verbalized for the reason that it issocially impolite to do so (see the next section for more discussion). Thus, the inclusive
interpretation is not necessarily the intended one and yet the exclusive interpretation cannot be made explicit. The speaker may leave it open for the hearer to deduce the exclusive reading whereas the hearer is pragmaticall y discouraged to pursue the inclusive reading even though adopting the latter is to his or her advantage in reality.
To facilitate the hearer's or reader's choice between the inclusive and exclusive reading of "or", it would be desirable for the English language to provide some procedural
aid in the course of comprehension. As a matter of fact, such an expectation, howeverconstant, has been partly lexicalized. Specifically, the speakers of English can sometimes
clarify or iterate his intention for an exclusive reading by adding the alternative intensifier or focus marker "either". Thus, for (8), we can explicitly say:
(8')

5.

For booking information, call either 3840684 or 3840687.

"or" and "and"Now, let's move to the second question we raised in the above section: given the two
possible meanings of "or", why do we generally assign the first meaning to the word?
The interpretation of "or" as truth-functionally inclusive seems to create an issue thatneither the purely exclusive account nor the ambiguity account does: "or" can be conf usedwith "and" since both P 1 & P2 and P, V P2 result as true when P, and P2 are true.
However, this apparently worrying overlap does not lead to practical confusion for thereason that "and" and "or" are complementary in their usage. On one hand, "and", usedin the affirmative sentence, indicates the simultaneity of assertion whereas "or", used in

32

the negative sentence7 conveys the simultaneity of negation, as shown below.
(13)

a.
b.

I speak Chinese and English.
I don't speak Chinese or English.

c.

He never smokes or drinks.

On the other hand, with "and", the conjoined items are taken as a whole; with "or",the conjoined items are taken as altematives. There are times when "and" is used in thenegative sentence. For instance,
( 14)

a.

I don't s peak Chinese and English.

b.

I don' t speak Chinese or English.

When this happens, it is generally the case that, of the languages mentioned (two in thiscase), he or she does not speak Chinese and English. By contrast, as in (14b), it is generally the case that the speaker speaks neither of the two languages under discussion,
rather than two of a set. Another possibility in (14a) is that the speaker may be able tospeak one of the two languages, but cannot speak both. In other words, "Chinese andEnglish" here is taken as a unit rather than a combination of two individuals. Yet, thisway of processing is applicable to a series conjoined by "or" . Thi s is further supportedby the distinction of the following pair:
( 15)

a.
b.

Do you speak Chinese and English, Tom?
Do you speak Chi nese or English, Tom?

Tom can' t answer "yes" if he speaks just one of the two languages in (1 5a), but hecan do so in (15b) if he speaks either or both of them.
Let's now retum to the cases where the possible inclusive reading actually yields tothe exclusive interpretation. In (1 1), repeated as (16) below, we argued that Tom could
legitimately take both an apple and a banana without offending the speaker if he is hungry:( 16)Tom, take an apple or a banana if you feel hungry.

However, we would like to contend here that despite the liberty allowed in this situation, Tom is not supposed to take both an apple and a banana because the exclusive
interpretation is actually intended by the speaker. Our reasoning is that if the speaker had
intended Tom to eat both an apple and a banana, he or she would have used "and" insteadof "or". To support this line of reasoning, we need to resort to Grice's Cooperative
Principle, a principle supposedly at work beneath conversational behavior. The Maximof Quantity stipulates that speakers need to make their conversational contribution as

7

Chinese EFL learners often mistakenly use "and" for "or" in negati ve sentences when the items
conjoined are not treated inclusively as taken from a set. e.g. I don't speak French and English.

"OR" at the Semantic-Pragmatic lntelface

33

informative as they can but not overinfonnative. (Grice 1975) Since "and" unequivocally conveys the inclusive reading while "or" depends heavily on the context for an inclusive interp retation, "and" is more explicitly informative than "or" on this point. They
form what Horn (1984) terms an ordered pair on a scale <and, or>, yielding the scalar
implicature that if P V Q, then-., (P&Q) (for further support, refer to Sadock 1978). Since
the implicature is only implicitly conveyed and, what is more, cancelable, there is room
for the hearer to ignore it. That is why Tom can in fact eat both an apple and a banana.
As for the reason why the speaker opts to use "or" instead of "and" in this case, a plausible explanation is that the speaker probably reckons that an apple or a banana suffices
to ease hunger. That being the case, aski ng Tom to eat both would be an imposition thatthreatens Tom 's negative face (Brown and Levinson 1987). The use of "or", but not"and", leaves the choice to Tom. The same is true of the following examples:
(17)

a.
b.

If you want to join our party, bring with you some candies and fruits.
If yo u want to join our party, bring with you some candies or fruits.

Although there is no violation of the speaker's expectation in both (17a) and ( 17b)
if the hearer turns up in the party with both candies and fruits, the latter involves less ofan imposition than the former. Thus, depending on both the Quantity Maxim of the
Cooperative Principle and the Tact Maxim (minimize cost to hearer; maximize benefit tohearer) of the Politeness Principle (Leech 1983), the speaker, who doubtless welcomesmaximal contribution from each participant, may fulfil his or her purpose without exerting imposition thanks to the <and, or> -based mitigation. It follows that the sole resort
to the informativeness requirement subsumed under the Cooperative Principle is notenough to account for the inclusive interpretation of "or" as against " and" in these cases,
where characteristically such face-threatening acts (FrAs, Brown and Levinson I 987) as
requests, offers, and advice are performed.
Speaking in terms of implicature, we can further distinguish the inclusive readingfrom the exclusive reading because the implicatures associated with each are strengthened, contradicted, and canceled in different ways. For instance,(1 8):. - .

a. You'll get a toy dog or a toy car for your birthday.
b. You' ll get a toy dog or a toy car for your birthday but not both. [strengthened]c. You'll get a toy dog or a toy car for your birthday or both . [pragmaticallycanceled because the speaker would use "and" instead of "or" if he intended to give both]d. You' ll get a toy dog or a toy car for your birthday or not both . [redundant]e. You' ll get a toy dog or a toy car for your birthday but both. [contradicted]

Now compare the following:
(19)

a.

To qualify, you need to obtain an A in phonology or syntax.

34

b.
c.
d.
e.

To qualify, you need to obtain an A in phonology or syntax but not both.
[pragmatically canceled because this does not accord w ith reality]
To qualify, you need to obtain an A in phonology or syntax or both.
[stre ngthened]
To qualify, you need to obtain an A in phonology or syntax or not both.
[redundant]
To qualify, you need to obtain an A in phonology or syntax but both. [contradicted]

Thus, we can rewrite (19a) more explicitly as ( 19f).
f.

To qualify, you need to obtain at least an A in phonology or syntax.

Pragmatic implicatures, including those based on "or", are reinforceable. For
instance, we can say They sang or danced, and they may have done both. If you bet that
Jack will sing or dance in tomotTow's party, you win if he does both; and if you promise
to sing or dance, and do both, you keep your word . By contrast it is a contradiction to
say Jack didn't sing or dance, but he may have done both. Likewise, if a sign says No
parking or loitering, you can' t excuse yourself by saying that you both parked and loitered. Laws depend on explicit meanings, rather than on pragmatic implicatures.

6. The derivative usages
By adopting the inclusive account of "or", we will also be better able to answer thefollow question: Are the different senses of "or" as listed in the dictionary intrinsicallyrelated (which may lead to the polysemy account) or not (which may lead to thehyponymy account)? The answer is yes. We claim that all the senses have been derived
and more or less conventionalized from the semantic inclusiveness of "or" by virtue ofpragmatic strengthening. Let's examine the usages by considei;ng the appositional "or"first. It is used in such contexts as when the speaker or writer attempts a more exact, or
simpler way of speaking, as in (3), repeated here as (20):(20)

Some people suffer from acrophobi a, or fear of great heights.

On the exclusive reading, the alternatives conjoined by "or" are such that they cannot be simultaneously chosen. This works well in the explanation of "or" in contexts
where " or" is used to indicate strong imposition of a particular line of action typical ofadvice, admonition or threat, as shown in (6), repeated here as (21):(2 1)Stand still or you will get killed.

The illocutionary force in speech acts of those kinds is basically pragmatically determined. The speaker strongly intends the first option is to be accepted. The alternatives
are totally unbalanced to the effect that the first alternative, which is believed to benefit

"OR" at the Semantic-Pragmatic Interface

35

or at least bring no harm to the hearer, is to be selected, whereas the second alternative,
if chosen, is said to bring undesirable consequences to the addressee. In fact, the imbalance is more of a qualitative than a quantitative nature. More often than not, the second
alternative is something beyond the hearer's control. Consequently, the hearer is actually left no other choice but to adopt the first alternative, a line of action prescribed by the
speaker. Since the second alternative is translatable as a consequence from not taking thefirst alternative, the otiginal compound sentence is equal to a conditional sentence. For
example, (2 1) can be rewritten as :
(21')
(21")

If you don' t stand still, you will get killed.
If you stand still, you will [probably] not get killed.

The need to express a forced choice is so strong and pervasive that the exclusive
reading of "or" gets lexicalized ("or else" meaning "otherwise") so that an inclusive reading is literally avoided, as in (22) :(22)

Go quick, or else you' ll mi ss the bus.

However, the purely exclusive account fails to explain cases like (20) since opting
for either of the items conjoined by "or" does not lead to the falsification of the statement.
Rather, the fact that both of the items can be true, though in different contexts (e.g. fordifferent people), cotTesponds to the inclusive reading of "or". What we process additionally is that the second item is "better" (here, more accessible to the general public)
than the first in some pragmati c ways, as often evidenced by the use of the following
expression in bold face:
(23)
(24)

Tom is kind or more exactly generous.
The child was born late last rught or rather early this morning.

Clearly, "or" in this usage serves to introduce new knowledge without affecting communicative intelligibility, though it is more effortful.
The neutralization of the incompatibility between or among the alternatives leads toanother semantic fu nction of "or"-expression of approximation, as sho~n in (4), repeated here as (25):(25)

His school is two or three miles away from his home.

Although the distance between one place and another is absolute (if it is 2 miles, it
can' t be 3 miles at the same time), the estimation of it can involve a certain range, within which neither a person with an estimate of 2 miles nor a person with an estimate of 3
miles can be held as wrong. In other words, for the approximate reading, as in "two or
three miles", the solution is that "or" is allowed an inclusive reading. Like the sense ofcompelling choice, this sense of approximation is also lexicalized into an unequivocal
phrase-"or so".
The final usage associated with the inclusive account of "or" is shown in (5), repeat-

36

ed here as (26):(26)

Rain or shine, I'll go.

Here, we have an extreme case because the two alternatives are not j ust incompatible but conflicting with each other. Generally, only one alternative is possible. However,
if "or" takes an inclusive reading, the speaker will mean that he will not decide to go justin one of the two conditions. Now that raining and shining are two contrary situations
figuratively representing the favorable and unfavorable conditions respectively, the speaker intends to convey the message that he is determined to go regardless of the external
conditions.

7.

Conclusion

In this article, we demonstrated that the different usages of the word "or" could attaina unified interpretation. We argued that this interpretation was available if we treated "or"as inclusive. In order to tackle the semantic underspecification, this paper, while drawing on existing studies, argued that we depend on pragmatic factors including pragmatic
principles and contextual information to determine whether just one of the disjuncts is
intended and allowed, or more than one of them is allowed though not intended. It wasstated that under conditions where one proposition containing only one of the disjuncts
can be true in the possible world projected by the speaker or the hearer of the utterance,
the exclusive reading prevails. An inclusive reading is possible when propositions containing more than one of the disjuncts can be true in the possible world projected by the
speaker or the bearer of the utterance. Yet, even in situations where the inclusive reading is allowed, the exclusive readi ng is generally the preferred interpretation due to themechanism of <and, or> scale. In these situations, the speaker may have chosen to appear
ambiguous by using the inclusive "or" and let the hearer to work out the unambiguous
exclusive meaning. What is at work here is not only the Cooperative Principle (particularly the informativeness requirement), but also the Politeness Ptinciple (particularly theTact Maxim). The tendency of assuming the exclusive reading is so strong in the overwhelming majoti ty of situations that "or" has acquired the exclusive reading as a conventional implicature. Also, we explored some special usages of "or" (notably approximation, concession and imposition), suggesting that these usages can be accommodated
and explained if the inclusive account is adopted, thus invalidating the possible homonymic approach. T he discussion suggested that communicators' needs give rise to grammaticalization and conventionalization.
Language is not merely a matter of truth or falsehood. Its users may intentionallydeflect from exactly communicating the truth or communicating the exact truth. If thephenomenon of pragmatic slack (Lasersohn 1999) or loose tallc (Sperber and Wilson
1985) is such evidence, the use of "or" as shown in the present paper, to no less degree,tells the same story: in the course of utterance comprehension, cooperative hearers do not"OR" at the Semantic-Pragmatic Interface

37

have to exhaust the expressive potential of underspecified words or utterances. They infer
intentions and decide on the very interpretation consistent with the shared contextual
information and pragmatic principles. The underspecification of lexical items, or thewhole sentences, leaves room for the interlocutors to negotiate meaning.

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