After all can mean ‘in spite of what was said before’ or ‘contrary to what was expected’. After all usually goes at the end of a clause.
- I’m sorry. I can’t help you after all.
- I expected to pass the test, but I failed after all.
After all can be used to introduce an important argument. With this meaning, it can go at the beginning or end of a sentence.
- OK, I will do the washing up. Somebody has to do it, after all.
- I think we should let him decide what he wants to do. After all, he is a big boy now.
After all does not mean ‘finally’, ‘at last’ or ‘in the end’.
- After the show we had dinner and went to the park; then we finally went home. (NOT …after all, we went home.)