The Meaning of By Now
Shinya Hirasawa
University of Tokyo
The present study explores the meaning of by now (now: the speaking time).
Quirk et al. (1985: 692) note that “By refers to the time at which the result of anevent is in existence,” using the example sentence She should be back by now (butI’m not sure). They do not explicitly state whether the element of inference
suggested by should is essential to the use of by now in the example, although it
actually is. With regard to this matter, Leech and Svartvik (2002: 87) indicate,using the sentence The wound should have healed by now, that one often uses by
now when one is not certain that the event has happened and that it is otherwise
more preferable to use already. It is tempting to assume that the concept ofinference seems to be the key to the correct use of by now.
However, there is an example where by now sounds strange even though it
is used with an expression associated with inference.
(1) Taro: When will Ken be coming back to Japan? I thought he said hewould some time next month, but …
Miki: *He must be back by now, because he wrote in his blog yesterdaythat he’d eaten Japanese food for the first time in six months.
One must replace by now with already for Miki’s response to sound natural inthis case. Also, there are examples where, even though there is no inference
involved, by now sounds natural.
(2) We all know what you did by now. Everyone hates you by now.
(3) As godfather to the boy and longtime friend of the father, Renzo has
been participating in this grim saga for seven years, and by now there islittle of anything left to say.

(Paul Auster, Sunset Park)(4) I turn back and find him ripping the adhesive tape off his nose andpulling the feeding tube out of his stomach. I grab hold of his hand but
the tube is by now all the way out and a milky liquid pools into the bed.
(The Corpus of Contemporary American English)
Reflecting on all of the examples provided above, the present study argues that

by now is used when the speaker draws on the knowledge that the probabilityof the occurrence of the event modified by by now increases over time. In (1), theground on which Miki bases her inference is the fact that before theconversation Ken wrote in his weblog that he had eaten Japanese food. No
progressive increase in the probability of Ken’s being back in Japan is involved
here, hence the unnaturalness of (1). In the natural-sounding cases where no
expression of inference is needed (e.g., (2), (3) and (4)), other expressions (e.g.,all, everyone, left and all the way) suggest increasing certainty over time. In othercases, the non-inferential use of by now (e.g., *She is back by now) sounds strange,
because one does not usually evoke the probablistic change that leads up to thespeaking time, if the statement is a report on some present state about which
the speaker knows for certain. If there is any suggestion that some kind ofinference is involved (e.g., Susan should be back by now), then by now sounds
natural because, when hearing an inference, the hearer is usually prompted tothink that there should be some past event that serves as grounds for theinference (e.g., Susan left the store more than 90 minutes ago). In such a case, thehearer is likely to evoke the increasing certainty over time (e.g., from 90
minutes ago to the speaking time).
Our hypothesis can also explain why may, might, perhaps and possibly are alittle less likely to co-occur with by now than should, must and probably.
Increasing certainty over time is more readily evoked when a considerable
amount of time has already passed, in which case the evoked certainty has
already reached a rather high level when the speaker evokes it.
Finally, we point out that this increase in certainty has no bearing on othertemporal uses of by (Compare the unnatural sentence *Susan left the store at 5:30
and by now she’s home with the natural sentence Susan left the store at 5:30 and bysix she was home).
References
Auster, Paul (2010) Sunset Park. London: Faber and Faber.
Davies, Mark. (2008-) The Corpus of Contemporary American English: 425+million
words, 1990-present. Available online at http://www.americancorpus.org.
Leech, G. N. and J. Svartvik (2002) A Communicative Grammar of English. 3rdedition. London: Longman.
Quirk, Randolph, Sidney Greenbaum, Geoffrey Leech, and Jan Svartvik (1985)
A Comprehensive Grammar of the English Language. Harlow: Longman.