“Dost” is the Early Modern English conjugation of “do” for “thou,” essential for questions and emphasis in poetic and dramatic dialogue. It appears throughout Shakespeare and devotional verse to maintain grammatical authenticity and rhythmic precision. Its use signals intimate or urgent address, and its obsolescence now marks it as a hallmark of elevated or period diction in literary contexts.

Dost is the second-person singular present tense of "do" used with "thou." The conjugation goes: I do, thou dost, he/she/it doth, we/you/they do. Students must master this for reading Early Modern English poetry and drama. "Dost" appears constantly in Shakespeare, the King James Bible, and Renaissance poetry. Pronunciation: "dost" rhymes with "host," not "cost." In questions, inversion occurs: "Dost thou know?" In negations: "Thou dost not know" or "Dost thou not know?" Understanding dost is essential for scanning meter in Renaissance poetry, as it provides rhythmic variation. By the 18th century, "thou/thee/thy" forms were disappearing from standard English, surviving mainly in religious contexts and poetry.