Student or Learner
if someone hits me accidentally, and she said sorry, should I say that's fine or you are fine? Since I remember that happened to me and I said sorry to the guy and he said you are fine.
What is the difference between these two phrases?
There's no difference. They're just two of many informal, colloquial terms people use to accept an apology, like 'no problem', 'that's OK', 'no worries', 'forget it', 'no harm done', 'I'll live', 'Don't worry about it' etc.