In case there should be any dispute, you should keep your original, marked documents for every assignment that you have done. Plagiarism All work submitted for assignments should be your own. If you submit someone else's as if it were your own, that is a form of cheating known as plagiarism. The worst case is when the other person does not know that you have copied their work. On the other hand, if the other person willingly allows another to use their work, they are party to the cheating and equally culpable.
Plagiarism is one of the worst blights on the teaching-learning scene.
If you commit it, you are building your life on deceit and that is a dangerous, damaging way to live. Worse still, widespread plagiarism means that assignments cease to be a reliable means of assessment and so more weight has to put on examinations. In principle, the weight given to assignments should reflect their great importance in the teaching-learning process. Because of plagiarism, it frequently has to be much less. So plagiarism by some students has bad consequences for the whole class.