1. He didn't have enough money to live on.
2. He speaks so softly that it's difficult to understand him.
He doesn't speak loudly enough for us to understand.
He speaks too softly for us to understand.
3. He is tall enough to touch the ceiling.
He is so tall that he can't touch the ceiling.
4. The coffee was so strong that he couldn't go to sleep.
He drank such strong coffee that he couldn't go to sleep.