Q. Is it OK to submit work as my own that I've worked on with another student?
Unless you have been told to work in a group, you must not submit work for assessment that isn't entirely your own work.
Both you and the other student involved would be guilty of the academic offence of collusion if you did this. If you re-used another person's work without their knowledge, you would be guilty of cheating and plagiarism.
You should also note that it is unacceptable practice to submit work where you have had the help of friends, family members, editors. etc. Anything you submit must be your own work.