Is there any difference in these sentences?

  1. You can go outside when you complete your work.

  2. You can go outside when you have completed your work.

Are they both interchangeable? If not then what is the difference between them?

  • 2
    They mean the same thing although I would prefer "after" instead of "when" in the first example. Commented Jun 15, 2020 at 17:10
  • It appears that the first sentence (present simple) is denoting a fact or general habit that would apply in all situations when the work is complete. This is a common feature of the present simple. Every time you complete your work, you can go outside. However, the second (present perfect) seems to be referring to the current work assignment only. Commented Jun 15, 2020 at 17:12

1 Answer 1


The first sentence sounds a bit odd, but the second sentence works for me.

If we are talking about an action in the adverbial clause that takes place over a period of time, we generally prefer the present perfect. Consider this example:

• After I have written this book, I am having a holiday. (not After I write...)

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