2

1, If you have not received the letter by February 18, please let us know by email.

2, If you do not receive the letter by February 18, please let us know by email.

Both 1 and 2 are talking about the things that may happen in a few weeks later, and I have seen that 1 and 2 are adopted on some universities's web sites.
Does this mean that 1 and 2 are equivalent?
If not, what are their differences then?

  • 1
    Did you mean to say "letter" instead of "lettet" in your second sentence? – levininja Feb 3 '15 at 21:20
2

We can say:

If the swelling does not go down by tomorrow evening, take two more of these pills.

or

If the swelling has not gone down by tomorrow evening, take two more of these pills.

If there is a nuanced difference between them, 99.9% of native speakers won't be able to tell you what that difference might be.

We can also say:

After a week, the swelling will have gone down enough that you can put your full weight on your foot again.

That's the future perfect.

  • So what's the nuanced difference? – Pacerier Jan 12 '18 at 21:23
  • It's the difference between action-in-progress and action-finished. – Tᴚoɯɐuo Jan 13 '18 at 0:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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