I want to talk to someone and make sure something is done. How to express this meaning using the word confirm? I'm not sure whether it should be confirm to sb or confirm with sb. Is there another way to say it?
With is correct:
I'd like to confirm with you that you will finish the report by Thursday.
You can also request confirmation:
Please confirm that you'll finish the report by then.
I need your confirmation that you'll do it on time.
With this sense, you can also confirm something for someone:
Let me look at my calendar to confirm that for you.
That is, to act on their request for confirmation.