when we are using DO as auxillary verb the main verb used should be in which form, base form or V1? Example :I do understand. Here 'Understand' is in Base form or V1?

  • Base form is the simple answer. V1 is the simple present tense where, as it happens, almost all verbs have an identical base and plain form: "I do understand" ~ "I/you/we/you/they understand. Hence the confusion.
    – BillJ
    Jan 22, 2020 at 18:42

1 Answer 1


After any part of do (do, does, did, done, don't, doesn't, didn't) the verb it governs is always in the base form.

Edit: I recognise "V1" from questions here as terminology which is used in TESOL, but it is unknown to most English speakers who are not TESOL teachers, and I didn't know what it meant without looking it up: it appears to mean the base form, so I don't understand (!) your question.

  • My question is that pure base from of verb which is different from V1( present plural form) is used after Do(does/do/did) or V1( present plural form)? My doubt is that in the example " I do understand". Understand is pure base form or V1( plural form).
    Jan 22, 2020 at 17:00
  • Right. If V1 means "plural form" (different from the base from for precisely one verb in the language: are vs be) then the answer is "base form". But this site uses "V1" and "base form" interchangeably.
    – Colin Fine
    Jan 22, 2020 at 17:43

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .