The present participle, the past participle and the infinitive are the three non-finite verb forms in English.
Present participles are used to form continuous tenses:
- I am coming
- she is singing
Verbal nouns or gerunds have the same form as present participles, but behave as nouns rather than verbs. For example, a verbal noun can act as the subject or object in a sentence:
- Playing football is good for you. [subject]
- I hate telling lies. [object]
Past participles are used in the formation of perfect tenses and passive constructions:
- I have gone
- we had finished
- he was caught
- they were beaten
Infinitives are often used after other verbs. A modal verb is followed by a bare infinitive [infinitive without to]:
- we can go
- they will come
A lexical verb is followed by a to-infinitive:
- we want to go
- they like to sing
Some verbs must be followed by a verbal noun, others by an infinitive. Some verbs can be followed by either verbal nouns or infinitives:
- I like singing
- I like to sing
Participles and verbal nouns can be used as adjectives:
- an interesting book
- a frightened child
- a washing machine
- a dining room