Supply the suitable form of the infinitive of the verbs in brackets after can and could.

1. We'll go away together if you like. We ... easily ... (catch) the 3:40.
2. He was so weak that he could ... (not lift) his head.
3. How could you ... (make) such a mistake as to suppose that I was younger than you?
4. I don't believe a single word of his; he can't ... (fail) to learn the news before us.
5. What, can she still ... (sleep)?
6. She has a university education and could ... (make) a career for herself if she hadn't married.
7. He could ... (buy) a new car if he had managed to save enough money.
8. Our baby was only nine months but he could ... (stand up).
9. Boris was an excellent tennis player. He could ... (beat) anybody.
10. What could ... (put) such an idea into your pretty little head?