Letter in the March 2011 Instinct magazine expressing inflection rage:
As a retired professor of English, I must call attention to the grammatical error in the latest issue: The past tense of the verb sink is sank, not sunk (that’s the past participle, as in, “The Nazis had sunk many war vessels” ["Editor's Letter," Dec. 2010/Jan. 2011]. In the future, I would be happy to copy-edit any editorials, since whoever does your copy editing has obviously fallen down on the job. A concerned but very avid reader…
Ben A. in Los Angeles, CA
A snappy, jokey reply from the editors accepts the criticism, but attributes the error to the editor Mike Wood, rather than the proofreaders:
Mike’s just rambling on and on in those “Editor’s Letters” moments before we have to pry the copy from his clammy hands to deliver the magazine to the presses!
All the parties in this exchange seem to believe that there is One Right Way to form the past tense of a verb, and for SINK this way is sank.
Both beliefs are flawed, the second dramatically so, though I have a speculation about the source of the professor’s rage.
One Right Way comes in many variants (for an inventory of postings on ORW, up to 6/28/09, see here), but the one here — denying the possibility of variation in inflectional forms (at least in the standard variety) — is especially simple, and simply false, as a glance at the morphology section of any scholarly grammar will show. There you will find many variant forms, like dreamed and dreamt as PST (and PSP) of DREAM. (The variants are often distinguished stylistically, as in the case of DREAM.)
So the only substantive question is the status of sank and sunk as the PST of SINK. I assume that the retired professor uses only sank himself, but his status as an English professor gives him no automatic insight into other people’s usage, and in this case all the evidence indicates that his usage is not the only standard variant.
OED2, AHD4, and NOAD2 all list both variants for the PST of SINK, without comment, and the OED supplies the further information that the variation has been around since Old English (in the spellings sanc/sank and sonc/sonk). Paul Brians in his Common Errors doesn’t mention the variation (though he does prescribe on some other variant PSTs; see below), and MWDEU specifically admits both usages:
sink Both sank and sunk are used for the past tense of sink. Sank is used more often, but sunk is neither rare nor dialectal as a past tense…
with citations of both, including
Then I sunk back never again to blaze perhaps — Robert Frost, letter, 8 July 1935
. . . the squall that sunk the Pride of Baltimore — M. Murray, Science News, 2 Aug. 1986
Why should the professor have gotten this so wrong? Perhaps because he was generalizing from other verbs for which the three-vowel pattern / ɪ – æ – ʌ / for PRS – PST – PSP has been variably leveled to the two-vowel pattern / ɪ - ʌ - ʌ /: in particular, DRINK, SING, and SHRINK. Brians proscribes the /ʌ/ PST for all three of these verbs — the fact that he has entries for them indicates that the variants are in fact very common — and sources like AHD4 and NOAD2 don’t list them as variants. So they haven’t achieved status as standard forms yet, though they are certainly advancing.
Shrunk for shrank is especially common, as in the sometimes-derided Disney movie title Honey, I Shrunk the Kids (1989). Then prejudice against PST shrunk might well have contaminated the very phonologically similar PST sunk.
[Note: There is a separate leveling that is widespread in non-standard American English: the leveling of PST and PSP, usually by the spread of the PST form (more frequent in texts) to serve also as PSP (less frequent in texts), as in They have drank the Kool-Aid. So there are two levelings, sometimes running in opposite directions.]