- Simple past tense and past participle of shrink.
In casual use, found even in careful speech, interchangeable with shrank; in careful formal use, only used for past participle "I have shrunk", while shrank is used for the past tense "I shrank". Compare sank/sunk. Grammatically, shrink is a Germanic strong verb, hence conjugated via ablaut (change of vowel, rather than adding -ed), but these are irregular in modern English, hence the inconsistent usage.
The 1989 movie Honey, I Shrunk the Kids (formally: Honey, I Shrank the Kids or Honey, I've Shrunk the Kids) is an example of the prevalence of the casual form.
- "shrunk/shrank", Paul Brians
- "ON LANGUAGE; How 'Shrunk' Snuck In", by William Safire, July 16, 1995, New York Times