Is it OK

'Deadlines over' is wrong. I don't understand how deadlines are associated with hanging out and playing.

It seems like deadline over is correct. Should I use 'priority here', not 'prioritize', or something else more natural?

AnonymousIt seems like deadline over is correct.

No, it isn't, as I said.

AnonymousYou'd better prioritize

... prioritize your [objectives / goals / time] ...

Anonymousover hanging out and playing

Suggestion: ... so that you don't waste so much time hanging out and playing.

(I'm guessing what you want to say.)

CJ

This post is to ask how native speaker would express priority.
I've heard 'put x first'. I doubt it's correct.

AnonymousI've heard 'put x first'

That is possible, but not in your example sentence.

You need to put your homework first, instead of running out to play with your friends.

OK, thanks. I don't know if it would sound natural if there are more than one actions,
expanding your example a little more:
You need to put your homework first, instead of running out to play with your friends, second hanging out with your boyfriend, third going shopping, fourth playing Nintendo.

AnonymousYou need to put your homework first, instead of running out to play with your friends, second hanging out with your boyfriend, third going shopping, fourth playing Nintendo.

No.

I can't think of a good example now. Perhaps you mean the following is correct and natural:

...put x first... (this is OK as said earlier)
...put x second...
...put x third...

Anonymous. Perhaps you mean the following is correct and natural:...put x first... (this is OK as said earlier)...put x second......put x third...

No; only 'first' (= 'before anything else') is a natural utterance. We do not list priorities like that in any native conversation, other than in some sort of listing of instructions or processes in business and sc