NOTE: as
with the present infinitive, there are situations where the to
is omitted, e.g. after most modal auxiliaries.
The
perfect infinitive:
to
have + past participle, e.g. to have broken, to have
seen, to have saved.
This form
is most commonly found in Type 3 conditional sentences, using
the conditional perfect, e.g. If I had known you were coming I
would have baked a cake.
Examples:
Someone
must have broken the window and climbed in.
I would
like to have seen the Taj Mahal when I was in India.
He pretended
to have seen the film.
If I'd
seen the ball I would have caught it.
The
continuous infinitive:
to
be + present participle, e.g.to be swimming, to be
joking, to be waiting
Examples:
I'd really
like to be swimming in a nice cool pool right now.
You must
be joking!
I happened
to be waiting for the bus when the accident happened.
The
perfect continuous infinitive:
to
have been + present participle
Examples:
to have
been crying
to have
been waiting
to
have been painting
The woman
seemed to have been crying.
You must
have been waiting for hours!
He pretended
to have been painting all day.
The
passive infinitive:
to
be + past participle, e.g. to be given, to be shut, to be
opened