# -io
## Esperanto
### Etymology

From Latin -ia in country names.

### Pronunciation

* IPA: [ˈio]
* Rhymes: -io
* Hyphenation: i‧o

### Suffix

-io
* a place, usually a country, named after the root, whether that is a people, person, city, or river
    ‎andaluzo (“Andalusian”) + ‎-io → ‎Andaluzio (“Andalusia”)
    ‎Esperanto (“the Esperanto language”) + ‎-io → ‎Esperantio (“a notional Esperanto-speaking land”)
    ‎flandro (“Fleming”) + ‎-io → ‎Flandrio (“Flanders”)
    ‎japano (“a Japanese person”) + ‎-io → ‎Japanio (“Japan”)
    ‎Kaŭkazo (“the Caucasus Mountains”) + ‎-io → ‎Kaŭkazio (“the Caucasus (region)”)
    ‎Kolumbo (“Christopher Columbus”) + ‎-io → ‎Kolumbio (“Colombia”)
    ‎Niĝero (“the Niger River”) + ‎-io → ‎Niĝerio (“Nigeria”)
    ‎Novjorko (“New York City”) + ‎-io → ‎Novjorkio (“New York (state)”)
    ‎Romo (“Rome”) + ‎-io → ‎Romio (“the Roman Empire”)
    ‎ŝvabo (“Swabian”) + ‎-io → ‎Ŝvabio (“Swabia”)
* a science named after its practitioner
    ‎astronomo (“astronomer”) + ‎-io → ‎astronomio (“astronomy”)
    ‎biologo (“biologist”) + ‎-io → ‎biologio (“biology”)
    ‎kirurgo (“surgeon”) + ‎-io → ‎kirurgio (“surgery (branch of medicine)”)
* -ium; used to form the names of chemical elements
    ‎berilo (“beryl”) + ‎-io → ‎berilio (“beryllium”)
    ‎titano (“titan”) + ‎-io → ‎titanio (“titanium”)
    ‎Urano (“Uranus”) + ‎-io → ‎uranio (“uranium”)

#### Synonyms

* (place): -ujo for places named after their inhabitants: Anglujo (“England”)
* (place): lando is also sometimes used for places named after inhabitants: Svedlando = Svedio (“Sweden”)
* (science): scienco is used like a suffix with root words to form names of some sciences: vulkanoscienco = vulkanologio (“volcanology”)

#### Derived terms
## Finnish
### Etymology

From multiple sources, including extraction from words derived with -o from verb stems ending in -i, as well as from earlier and still dialectal -i(j)o, from -ja-i (for labial ai > o, compare plural forms of kala-type nouns), from -ja + -i.

### Suffix

-io (front vowel harmony variant -iö, linguistic notation -iO)
* Forms nouns from verbs or verbal stems.
    ‎itää (“to sprout”) + ‎-io → ‎itiö (“spore (of e.g. mushroom, moss)”)
    ‎valita (“to choose”) + ‎-io → ‎valio (“elite, select”)
* Forms nouns from other nouns, adjectives, numbers or their stems.
    ‎yksi (“one”) + ‎-io → ‎yksiö (“a one-room apartment”)
    ‎kolme (“three”) + ‎-io → ‎kolmio (“a triangle; a yield sign”)
    ‎neljä (“four”) + ‎-io → ‎neliö (“a square”); shorter form for a square meter

#### Declension

Possessive forms of -io (Kotus type 3/valtio, no gradation) :
first-person singular possessor
singular
plural
nominative
-ioni
-ioni
accusative
nom.
-ioni
-ioni
gen.
-ioni
genitive
-ioni
-ioideni -ioitteni
partitive
-iotani
-ioitani
inessive
-iossani
-ioissani
elative
-iostani
-ioistani
illative
-iooni
-ioihini
adessive
-iollani
-ioillani
ablative
-ioltani
-ioiltani
allative
-iolleni
-ioilleni
essive
-ionani
-ioinani
translative
-iokseni
-ioikseni
abessive
-iottani
-ioittani
instructive
comitative
—-ioineni
second-person singular possessor
singular
plural
nominative
-iosi
-iosi
accusative
nom.
-iosi
-iosi
gen.
-iosi
genitive
-iosi
-ioidesi -ioittesi
partitive
-iotasi
-ioitasi
inessive
-iossasi
-ioissasi
elative
-iostasi
-ioistasi
illative
-ioosi
-ioihisi
adessive
-iollasi
-ioillasi
ablative
-ioltasi
-ioiltasi
allative
-iollesi
-ioillesi
essive
-ionasi
-ioinasi
translative
-ioksesi
-ioiksesi
abessive
-iottasi
-ioittasi
instructive
comitative
—-ioinesi
first-person plural possessor
singular
plural
nominative
-iomme
-iomme
accusative
nom.
-iomme
-iomme
gen.
-iomme
genitive
-iomme
-ioidemme -ioittemme
partitive
-iotamme
-ioitamme
inessive
-iossamme
-ioissamme
elative
-iostamme
-ioistamme
illative
-ioomme
-ioihimme
adessive
-iollamme
-ioillamme
ablative
-ioltamme
-ioiltamme
allative
-iollemme
-ioillemme
essive
-ionamme
-ioinamme
translative
-ioksemme
-ioiksemme
abessive
-iottamme
-ioittamme
instructive
comitative
—-ioinemme
second-person plural possessor
singular
plural
nominative
-ionne
-ionne
accusative
nom.
-ionne
-ionne
gen.
-ionne
genitive
-ionne
-ioidenne -ioittenne
partitive
-iotanne
-ioitanne
inessive
-iossanne
-ioissanne
elative
-iostanne
-ioistanne
illative
-ioonne
-ioihinne
adessive
-iollanne
-ioillanne
ablative
-ioltanne
-ioiltanne
allative
-iollenne
-ioillenne
essive
-ionanne
-ioinanne
translative
-ioksenne
-ioiksenne
abessive
-iottanne
-ioittanne
instructive
comitative
—-ioinenne
third-person possessor
singular
plural
nominative
-ionsa
-ionsa
accusative
nom.
-ionsa
-ionsa
gen.
-ionsa
genitive
-ionsa
-ioidensa -ioittensa
partitive
-iotaan -iotansa
-ioitaan -ioitansa
inessive
-iossaan -iossansa
-ioissaan -ioissansa
elative
-iostaan -iostansa
-ioistaan -ioistansa
illative
-ioonsa
-ioihinsa
adessive
-iollaan -iollansa
-ioillaan -ioillansa
ablative
-ioltaan -ioltansa
-ioiltaan -ioiltansa
allative
-iolleen -iollensa
-ioilleen -ioillensa
essive
-ionaan -ionansa
-ioinaan -ioinansa
translative
-iokseen -ioksensa
-ioikseen -ioiksensa
abessive
-iottaan -iottansa
-ioittaan -ioittansa
instructive
comitative
—-ioineen -ioinensa :

#### Derived terms
### Anagrams

* oi

## Ido
### Etymology

Borrowed from English -ia, French -ie, Italian -ia, Russian -ия (-ija), Spanish -ia, ultimately from Latin -ia, from Ancient Greek -ία (-ía).

### Suffix

-io
* suffix denoting the country, region, domain, territory or province dependent upon the authority of a person
    ‎duko (“duke; duchess”) + ‎-io → ‎dukio (“duchy”)
    ‎episkopo (“bishop”) + ‎-io → ‎episkopio (“bishopric, diocese, episcopate”)
    ‎paroko (“parish priest, rector”) + ‎-io → ‎parokio (“parish”)
    ‎rejo (“sovereign, ruler, king, queen, monarch”) + ‎-io → ‎rejio (“kingdom”)

#### Usage notes

A common but false misconception is that countries that end with -ia in Ido, for example Albania, use this suffix when in fact it's part of the root itself. Though, -io at times can help shape country names to fit; Mexikia uses the extra i so not to be confused with Mexiko (“Mexico City”) at the same time resembling other country names.

#### Derived terms
## Italian
### Etymology 1

Unknown. Perhaps from Latin -ērium.

#### Pronunciation

* IPA: /ˈi.o/
* Rhymes: -io
* Hyphenation: -ì‧o

#### Suffix

-io m (noun-forming suffix, plural -ii)
* used with verb roots to derive nouns with durative, intensive or frequentative connotation; -le

##### Derived terms
### Etymology 2

From Latin -īvus.

#### Pronunciation

* IPA: /ˈi.o/
* Rhymes: -io
* Hyphenation: -ì‧o

#### Suffix

-io (adjective-forming suffix, feminine -ia, masculine plural -ii, feminine plural -ie) -io m (noun-forming suffix, plural -ii)
* Alternative form of -ivo

##### Derived terms
### Etymology 3

From Latin -ius.

#### Pronunciation

* IPA: /jo/, /ˈi.o/
* Rhymes: -io
* Hyphenation: -io, -ì‧o

#### Suffix

-io (adjective-forming suffix, feminine -ia, masculine plural -i or -ii, feminine plural -ie)
* added to nouns and adjectives to form adjectives meaning “having the quality of”; -y

### Etymology 4
#### Pronunciation

* IPA: /jo/ (stressed on the preceding syllable)
* Hyphenation: -io

#### Suffix

-io m (noun-forming suffix, plural -i)
* (uncommon) used with verb roots to derive simple deverbal nouns
    ‎sgravare (“to relieve, to lighten”) + ‎-io → ‎sgràvio (“relief, lightening”)

##### Derived terms
### Etymology 5

Borrowed from New Latin -ium.

#### Pronunciation

* IPA: /jo/, /ˈi.o/
* Rhymes: -io
* Hyphenation: -io, -ì‧o

#### Suffix

-io m (noun-forming suffix, plural -i or -ii)
* forms the name of chemical elements; -ium

##### Derived terms
### Etymology 6

From Latin -īvit via Vulgar Latin -īut.

#### Pronunciation

* IPA: /jo/, /ˈi.o/
* Rhymes: -io
* Hyphenation: -io, -ì‧o

#### Suffix

-io (non-lemma form of verb-forming suffix)
* (archaic, Dantesque) used with a stem to form the third-person singular past historic of regular -ire verbs

### Derived terms
## Latin
### Etymology 1

Suffix -ō on i-stems.

#### Suffix

-iō f (genitive -iōnis); third declension
* Used to form abstract nouns from verbs.

##### Usage notes

The suffix -iō is added to a verb to create a third-declension feminine abstract noun.
    Examples:
       legiō, from legō
       regiō, from regō

##### Declension

Third-declension noun.

##### Synonyms

* -tus

##### Derived terms
#### Further reading

* Sihler, Andrew L. (1995) New Comparative Grammar of Greek and Latin, Oxford, New York: Oxford University Press, →ISBN

### Etymology 2

Extension of -ō (possibly by rebracketing).

#### Suffix

-iō m (genitive -iōnis); third declension
* Suffixed to noun or adjective stems, forms various nouns designating persons that are characterized by or related to the base word, such as nicknames or names of professions.
* Suffixed to noun or adjective stems, forms certain nouns designating things; often described as a kind of diminutive.

##### Usage notes

Personal appellations ending in -iō appear to have often had a derogatory or pejorative shade of meaning, which in some cases resulted in a sense near that of a diminutive, as in the case of homunciō.

##### Declension

Third-declension noun.

##### Synonyms

* -ō, -ārius

##### Derived terms
### Etymology 3

From -i-ō. Ultimately from Proto-Indo-European *-yeti.

#### Suffix

-iō (present infinitive -iāre, perfect active -iāvī, supine -iātum); first conjugation
* Used to form factitive verbs from adjectives.

##### Conjugation

$^1$At least one use of the Old Latin "sigmatic future" and "sigmatic aorist" tenses is attested, which are used by Old Latin writers; most notably Plautus and Terence. The sigmatic future is generally ascribed a future or future perfect meaning, while the sigmatic aorist expresses a possible desire ("might want to"). $^2$The present passive infinitive in -ier is a rare poetic form which is attested.

##### Derived terms
### Etymology 4

From Proto-Italic *-jō, from Proto-Indo-European *-yéti (first person singular: *-yóh₂) after a consonant.

#### Suffix

-iō (present infinitive -ere, perfect active -ī, supine -um); third conjugation iō-variant
* Used to form some irregular third conjugation verbs.

##### Conjugation

$^1$At least one use of the Old Latin "sigmatic future" and "sigmatic aorist" tenses is attested, which are used by Old Latin writers; most notably Plautus and Terence. The sigmatic future is generally ascribed a future or future perfect meaning, while the sigmatic aorist expresses a possible desire ("might want to"). It is also attested as having a rare sigmatic future passive indicative form ("will have been"), which is not attested in the plural for any verb.

### Etymology 5

Ultimately from Proto-Indo-European *-yéti (denominative suffix). The question of how it came to be differentiated from third-conjugation -iō, -ere is still debated. Vine 2012 derives denominatives such as serviō from *serw-e-yé/ó- (with the thematic vowel *-e- before the suffix), proposing that unaccented Proto-Indo-European *-e- came to be assimilated in Italic to an immediately following *-y-. Alternative explanations include an Italic version of Sievers's law (that is, a prosodically conditioned development of postconsonantal *-y-* to *-iy- in certain contexts) or combination of the suffix with stems ending in *-i-. Some verbs may be derived from backformation from adjectives ending in -ītus, such as igniō, whose finite forms are attested later than ignītus (“fiery, glowing”).

#### Suffix

-iō (present infinitive -īre, perfect active -īvī or -iī, supine -ītum); fourth conjugation
* Used to form fourth conjugation verbs.

##### Conjugation

$^1$At least one use of the Old Latin "sigmatic future" and "sigmatic aorist" tenses is attested, which are used by Old Latin writers; most notably Plautus and Terence. The sigmatic future is generally ascribed a future or future perfect meaning, while the sigmatic aorist expresses a possible desire ("might want to").

##### Descendants

(from infinitive -īre:)
* Asturian: -ir
* Catalan: -ir
* Friulian: -î
* Galician: -ir
* Italian: -ire
* Occitan: -ir
* Old French: -ir
** French: -ir
* Portuguese: -ir
* Romanian: -i
* Spanish: -ir

### References

* ↑ Petersen, Walter, 1910. Greek diminutives in -ION; a study in semantics, pages 194-195
* ↑ Vine, Brent (2012) “PIE mobile accent in Italic: Further evidence”, in Benedicte Nielsen Whitehead, Thomas Olander, Birgit Anette Olsen, and Jens Elmegård Rasmussen, editors, The Sound of Indo-European: Phonetics, phonemics, and morphophonemics, Museum Tusculanum Press
* ↑ Ernout, Alfred, Meillet, Antoine (1985) “ignis”, in Dictionnaire étymologique de la langue latine: histoire des mots‎ (in French), 4th edition, with additions and corrections of Jacques André, Paris: Klincksieck, published 2001, page 308

## Old Spanish
### Etymology

From Latin -ium, from the adjectival suffix -ius.

### Pronunciation

* IPA: /ˈ-io/

### Suffix

-io
* (added to nouns) A suffix forming abstract nouns.
    ‎sennor (“lord, master”) + ‎-io → ‎sennorio (“dominion, jurisdiction”)

#### Descendants

* Spanish: -ío

## Portuguese
### Etymology 1

From Old Galician-Portuguese -io, from Latin -īvus. Doublet of -ivo.

#### Pronunciation

* (Brazil) IPA: /ˈi.u/, /ˈiw/ [ˈiʊ̯]
* (Portugal) IPA: /ˈi.u/

#### Suffix

-io (adjective-forming suffix, feminine -ia, masculine plural -ios, feminine plural -ias)
* -ive; -y (forms adjectives from verbs, indicating a tendency or inclination)
    ‎escorregar (“to slip”) + ‎-io → ‎escorregadio (“slippery”)
    ‎arredar (“to withdraw from”) + ‎-io → ‎arredio (“withdrawn, solitary”)

### Etymology 2
#### Pronunciation

* (Brazil) IPA: /ˈi.u/, /ˈiw/ [ˈiʊ̯]
* (Portugal) IPA: /ˈi.u/

#### Suffix

-io m (noun-forming suffix, uncountable)
* (informal) forms collectives
    ‎mulher (“woman”) + ‎-io → ‎mulherio (“a bunch of women”)

### Etymology 3
#### Suffix

-io m (noun-forming suffix, plural -ios)
* (chemistry) -ium (forms the names of chemical elements and isotopes)

### Etymology 4
#### Pronunciation

* (Brazil) IPA: /ˈiw/ [ˈiʊ̯]
* (Portugal) IPA: /ˈiw/

#### Verb

-io
* Obsolete spelling of -iu.

## Spanish
### Etymology

Borrowed from New Latin -ium, from Latin -um, based on Latin terms for metals, such as ferrum (“iron”).

### Suffix

-io m (noun-forming suffix, plural -ios)
* -ium

#### Derived terms
### Further reading

* “-io”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8, Royal Spanish Academy [Spanish: Real Academia Española], 2024 December 10

## Welsh
### Etymology

Variant of -o, initially after a stem that contained /j/ (for Brythonic /ɣ/ or from palatalization after a diphthong), later extended to other verbstems.

### Pronunciation

* IPA: /jɔ/

### Suffix

-io
* Forms verbnouns from verbs and other parts of speech.

#### Related terms

* -o (Forms verbnouns from verb stems ending in i̯)