10. I am unhappy, so I cannot go out with him.
\(\Rightarrow\) I am too unhappy for to go out with him.
11. They sang very well. I could invite them to the party.
\(\Rightarrow\) They sang very well for me to invite them to the party.
12. You are very young. You can't have a front-door key.
\(\Rightarrow\) You are too young to have a front-door key.
13. I am rather old. I can't wear that kind of hat.
\(\Rightarrow\) I am not young enough to wear that kind of hat
14. The ladder wasn't very long. It didn't reach the window.
\(\Rightarrow\) The ladder was too short to reach the window.
15. He hadn't much money. He couldn't live on it.
\(\Rightarrow\) He didn't have enough money to live on it.
16. He was furious. He couldn't speak.
\(\Rightarrow\) He was too furious to speak.