When to use the to infinitive
The infinitive form is used after certain verbs:
- forget, help, learn, teach, train
- choose, expect, hope, need, offer, want, would like
- agree, encourage, pretend, promise
- allow, can/can't afford, decide, manage, mean, refuse
- I forgot to close the window.
- Mary needs to leave early.
- Why are they encouraged to learn English?
- We can't afford to take a long holiday.
The infinitive form is always used after adjectives, for example:
- disappointed, glad, happy, pleased, relieved, sad, surprised
- I was happy to help them.
- She will be delighted to see you.
When to use -ing
The -ing form is used when the word is the subject of a sentence or clause:
- Swimming is good exercise.
- Doctors say that smoking is bad for you.
The -ing form is used after a preposition:
- I look forward to meeting you.
- They left without saying "Goodbye."
The -ing form is used after certain verbs:
- avoid, dislike, enjoy, finish, give up, mind/not mind, practise
- I dislike getting up early.
- Would you mind opening the window?
