I happened to come across a sentence in a school textbook as follows:

" All you need to do is keep that passion burning in you and never give up."

Why is the bare infinitive form "keep" used here? Can't we use "to keep" instead?

  • 1
    You certainly can. In cases like this where the infinitival is predicative complement, and the subject NP contains do in a relative clause, "to" can optionally be added.
    – BillJ
    May 10, 2019 at 17:11
  • 1: All you need do is wait. 2: All you need to do is wait. 3: All you need to do is to wait. They're all fine, though #1 is a bit "distilled, clipped" and #3 is a bit "wordy". But I couldn't endorse 4: All you need do is to wait. May 10, 2019 at 18:10
  • All you need to do is [you need [to]] keep that passion burning. May 10, 2019 at 18:13

1 Answer 1


You could certianly write:

All you need to do is to keep that passion burning in you>

But the form without "to" before the verb is far more common in my experience, and will sound more natural.

All you need to do is keep that passion burning in you.

In general sentences of the form

All you need to do is {verb} {object}.

will use a bare infinitive for {verb}.

  • All you need to do is run the perfect mile
  • All you need to do is go to the store.
  • All you need to do is let me know.
  • All you need to do is use the web site.
  • All you need to do is learn the procedure.
  • All you need to do is breath deeply.

Al the above are standard and common. "To" could be added before the verb on any of them, but it is not needed on any, and the form with "to" is now significantly less common. Using "to" would not change the meaning in any way.

Note that in the last case the verb has no object, but the form is stil valid.


A comment, but not the original question, asks about omitting the "to" in the "to do" part of tjhe sentences. This would give such forms as:

  • All you need do is run the perfect mile.
  • All you need do is to run the perfect mile.

Both forms are grammatical. I think the forms with "to do" are more natural, but I am honestly not sure about relative frequency of use here. Perhaps this should be a separ5ate question.

  • In all your example sentences, including the sentence in question, is is the verb, and the infinitive form whether 'bare' or 'to infinitive' cannot act as the verb. So the part comes after is (a copula) is a complement, not object, isn't it? May 10, 2019 at 23:02
  • Also, see the comment above by BillJ. May 10, 2019 at 23:11
  • @mahmudkoya have you understoof what BillJ said above in his comment? He is right. FumbleFinger too gave another explanation using ellipsis though I would not prefer that explanation. But if you are comfortable with that explanation it is fine. Because FF is completely correct in his explanation. May 11, 2019 at 0:26
  • @Man_From_India, what would you say about David Siegel's answer? May 11, 2019 at 2:31
  • @mahmudkoya He basically said the same thing. I am not the native speaker, so can't comment on whether adding or removing subordinator to makes it more natural or less. And similarly I have not done any research on my end to comment of the statistics he mentioned. Surely he did, or if he is a native speaker he can say based on his intuition. But one thing he missed to add, and which that I think is very important is that to is optional in predicate when the relative clause in the subject has do. That is all I can say about the answer. May 11, 2019 at 3:38

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