Verb + -ing form / infinitive

The -ing form is used

1. as the subject of a sentence: SMOKING is unhealthy

2. after prepositions: We are thinking ABOUT going to New York

3. after some verbs: I ENJOY swimming

The infinitive with to is used

1. to express purpose: We are studying hard TO PASS the exam

2. after some adjectives: It's DIFFICULT to find work these days

3. after some verbs: If you need any help, don't HESITATE to contact me

The bare infinitive (infinitive without to) is used 

1. after modal verbs: I SHOULDN'T eat so much chocolate

2. after the verbs had better, help, let, make, would rather/sooner: Don't MAKE me cry

1. There are verbs which can be followed by an -ing form or an infinitive with to with no change of meaning: She STARTED singing / to sing

Verbs followed by 'ing' or by 'to + infinitive' 1

2. There are verbs which can be followed by an -ing form or an infinitive with to, but with a change of meaning: forget, mean, regret, remember, stop, try. The infinitive with to is used with forget, regret, remember and stop when the act of forgetting, regretting, remembering or stopping comes first: I REMEMBERED to make the copies. The -ing form is used when it comes second: I REMEMBER posting the letter. Mean + -ing form means involve (Changing jobs MEANT changing house), whereas mean + infinitive with to means intend  (I've been MEANING to write to you for ages). Try + -ing form means experiment with (I TRIED taking a painkiller), whereas try + infinitive with to means attempt (I'm TRYING to sleep).

Verbs followed by 'ing' or by 'to + infinitive' 2