You can't change it once you've signed up
I do not understand why "have signed up" is used here.
To me, "You can't change it once you sign up" is correct grammatically.
What is different between "have signed up" and "sign up" in this sentence?
Thanks in advance.
Best Answer
The first option is the better one, as it's clearer and not harsh at all.
There's a sense of completeness about "once you've signed up": the deed is done, and you can't change it.
In contrast, "Once you sign up" is less clear, as it can be taken as a restriction even in the act of singing up. That is, the timing of the sign up event, and the point at which the restriction begins, is not clear.