Gerund (ing-form)

• has properties of both nouns and verbs
• is widely used in spoken and written language
• is always used when preceded by certain verbs
• after prepositions
• in some idioms

Infinitive

• is a basic form of verb
• can sometimes be used instead of gerund
• usually preceded by to-particle

Ing-form after verb

• always after certain verbs

admit, avoid, burst out, can’t help, consider, delay, deny, detest, dislike, enjoy, escape, feel like, finish, give up, go on, imagine, keep (on), leave off, mind, miss, prevent (from), put off, regret, risk, stop, suggest, understand

• with following verbs both ing-form and infinitive can be used without changing the idea

attempt, begin, can’t bear/stand, cease, continue, intend, propose, start, try

• NOTICE: with verbs go on and stop
• ing-form indicates continuing or stopping action
• infinitive indicates meaning

Ing-form after preposition

• ALWAYS

• preposition can be attached to
• verb: accuse of, devote to, insist on, keep from, look forward to, object to, prevent (from), stop (from), succeed in, think of
• adjective: afraid of, fond of, good at, interested in, proud of, tired of, used to
• notice especially the idioms be used to doing sg, used to doing

• noun: be in danger of, difficulty/trouble (in), the habit of, the hope of, the reason for
• ing-form occurs after following idioms: it is no good / no use / not worth while, it is a waste of time / money, there is no point in, it is worth (while)

 Notice: ing-form is also used

• after words busy, like, past
• in the following idioms:

The police caught the man driving the stolen car.

The lost child was found walking in the park.

We must not keep the others waiting.

The passers-by left the old woman lying in the street.

Indicating subject of ing-form

• if subject of ing-form is same as the subject of the whole sentence it is not repeated before the ing-form

• if the subject of ing-form is a noun, it is usually in basic form