Your friend doesn't understand his English homework. (offer)
I'll help him with his homework.
There's no milk in the fridge. (offer)
I'll go to the supermarket.
It's important to be on time for the lessons. (promise)
I won't be late. / I`ll be on time.
You cheated on the final exam. (promise)
I won't do it again.
You made fun of your classmate. ( promise )
I won`t make fun of you again.