Hi,
What is the difference between didn`t and hasn`t?
I have to say - "He didn`t pay." - It`s right?
We often interchange these, with no difference in meaning intended.
However, here are a couple of comments.
"He didn`t pay" - Just means that at some point in the past he didn't pay. This could be 50 seconds ago or 50 years ago.
"He hasn't paid" - Again, this means that at some point in the past he didn't pay. However, the Present Perfect tense also means that this past matter is important in the present.
eg 'He hasn't paid. Go and ask him to pay!'
Best wishes, Clive