Question 11: My sister always enjoys **listening** to classical music.

Question 12: I’ve put off **writing** the letter so many times. I really must do it today.

Question 13: They don’t have much money. They can’t afford **to go** out very often.

Question 14: I’m still looking for a job but I hope **to find** something soon.

Question 15: My mother can’t stand **staying** at home without doing anything.

Question 16: How long have you been able **to swim**, John?

Question 17: You must promise **not to be** late again.

Question 18: When I saw her in that funny hat, I couldn’t help **laughing**.

Question 19: They refused **to lend** him the money although he needed it.

Question 20: Please, don’t forget **to post** the letter for me today! It’s urgent.