Someone requested me doing something. I would reply him that

"I'll do it once I (have) finished it."

Which is correct?

  • The grammar aside, I don't understand the meaning. Once you've finished something it's already complete and there there is no reason to do it. It will be over when it's over is a common phrase (and the wording gives it meaning), but I don't know how to parse this one. How are do it and finish it being used differently? Do the two pronouns each refer to something different? – Jason Bassford Jan 9 at 15:41

These are grammatical:

I'll do it once I finish it.

I'll do it once I have finished it.

There isn't much difference between them except that the latter emphasizes the completion or achievement of the action.

However, using "it" twice in these sentences is odd in that it's ambiguous: It means that you're referring to the same thing.

  • Agreed about the ambiguity. A native speaker would generally say something like, "I'll do it once I finish the other thing," or maybe, "I'll do that once I finish this." – Canadian Yankee Jan 9 at 15:26
  • Oh, sorry for that confusion. I should say "I'll do XXX once I finish it.", I meant XXX and it are different things. – Zhang Jan 10 at 1:24

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.