Best Answer - Chosen by the Askerdo you mean: "ain't and won't"?
"ain't" is a negative form of 'to be' (am, is, are), thus:
'am not' = ain't (not is contracted here)
ex: 'I am not going to work today!' = 'I ain't going to work today!'
ex2: 'He is not heave, he's my brother.' = 'He ain't heavy, he's my brother.'
'won't' on the other hand is just a contraction of 'will not'.
ex: 'He will not come' = 'He won't come'
ex2: 'They will not take the exam until the teacher comes.' = 'They won't take the exam until the teacher comes.'
:)