VERBS, INFLECTIONS OF:-- Past indicative forms in -uPast indicative forms in u are very common in Shakespeare. Thus, "sang" does not occur, while "sung" is common as a past indicative. "Sprang" is less common as a past tense than "sprung" (2 Hen. IV. i. 1. 111). "Begun" (Hamlet, iii. 2. 220) is not uncommon for "began," which is also used. We also find
Past indicative tenses in u were common in the seventeenth century, but the irregularity dates from the regular Early English idiom. In A. -S. the second person singular, and the three plural persons of some verbs, e.g. "singan," had the same vowel u, while the first and third persons singular had a. Hence, though the distinction was observed pretty regularly in E. E., yet gradually the u and a were used indiscriminately in the past tense without distinction of person.
“I drunk him to his bed.