When you want to express “an event that occurred before the tense of the main clause” in an infinitive or gerund, you use the perfect infinitive (to have + past participle) and the perfect gerund (having + past participle).
Basic Rules
Uses of the perfect infinitive to have + past participle:
① It indicates a tense before the main clause: “He seems to have been sick.（It seems that he was sick）” ← seem is present, be sick is past
② It combines with a modal + have + past participle: “You should have studied harder.（You should have studied harder, but you did not）” ← regret about the past
③ As in “I'm glad to have met you. (I was glad that I met you),” it indicates an event (meeting) that occurred before the tense of the main clause (present)
Uses of the perfect gerund having + past participle:
① It indicates a tense before the main clause: “I'm proud of having graduated from this school.（I am proud that I graduated from this school）”
② It expresses a past event after a preposition: “Thank you for having helped me yesterday.” “She regrets having said that.（She regrets saying such a thing）”
The logical subject of the perfect form: Place “for + person” or “subject + seem/appear” before a perfect infinitive, and “possessive/objective case + person” before a perfect gerund.
She seems to have been ill yesterday.（It seems that she was ill yesterday）← seem present / illness past
You should have called me earlier.（You should have called me earlier, but you did not）← regret about the past
I'm sorry to have kept you waiting.（I am sorry that I kept you waiting）← past action
He is proud of having won the prize last year.← He is proud of a past event
She denied having stolen the money.（She denied stealing the money）← denial of a past event
Points to Remember
① Modal variations of the perfect infinitive:
- should have done: should have done (did not do it; regret)
- must have done: must have done (certainty about the past)
- might/may have done: may have done
- could have done: could have done (but actually did not)
- would have done: (subjunctive) would have done
② The logical subject of a perfect gerund:
- I remember his/him having said so.（I remember that he said so）
- The possessive his is traditionally considered correct, while the objective him is also acceptable in conversational English.
③ Verbs and adjectives that commonly take perfect infinitives: seem / appear / pretend / claim / proud of / sure of / sorry to / glad to / ashamed of。
④ Comparison of the simple infinitive and the perfect infinitive:
- He seems to be tired. (He seems tired now) ← same time
- He seems to have been tired. (It seems that he was tired) ← before the main clause
- Perfect infinitive to have + past participle: an event before the tense of the main clause
- Perfect gerund having + past participle: likewise, an event before the main clause
- Modal + have + past participle: conjecture or regret about the past
- seem / appear / be proud of / be sorry to + perfect form
- Logical subject: possessive/objective case with a perfect gerund
Practice
- Translate “It seems that he could not sleep well last night” into English using seem to have.
- Translate “You should have gotten up earlier” into English using should have.
- Translate “She regrets having talked about the accident” into English using having + past participle (regret).