Have done; did

[Xinfu]

-For those who:cool: have done:cool: (or did?) the exercise in class, please ignore this email.

(from an email sent to the students who were absent)

IN CLASS is like yesterday, which requires the simple past; do you think HAVE DONE is wrong?

[Rusty]

Both 'have done' and 'did' are valid and you'll hear both used. Which one is used depends on what point of view the speaker takes about the action.

[Xinfu]

Good answer. Thank you.