Infinitive forms: active, passive and perfect

The infinitive also has active and passive forms. The verb clean gives a regular example; the French meaning is included only to make the form easy to recognise.

The pattern is consistent:

• passive infinitive: to be + past participle;
• perfect passive infinitive: to have been + past participle.

For a regular verb, the past participle is usually V-ed. For an irregular verb, learn its third form: write → written, build → built, see → seen.

Examples

• Active: “The team expects to finish the work.”
• Passive: “The team expects the work to be finished.”
• Perfect passive: “The work seems to have been finished already.”

The infinitive tells us whether the action is done by the subject or received by it; the surrounding verb tells us when the action is understood to happen.