12. By reading aloud to the class, they do not gain much.
13. He had to wait several hours for the train, thus causing him to
lose a great deal of valuable time.
14. After listening to his lecture for an hour he became tiresome.
15. We listened attentively to his lecture, thus showing our interest.

72. INFINITIVES. The Infinitives are formed by the word _to_ and
some part of the verb or of the verb and auxiliary. For _see_ and
_play_ as model verbs, the infinitives are as follows:

PRESENT ACTIVE PRESENT PASSIVE
to see to be seen
to play to be played

PRESENT PERFECT ACTIVE PRESENT PERFECT PASSIVE
to have seen to have been seen
to have played to have been played

The word _to_ is frequently omitted. In general, other verbs follow
the same endings and forms as do the infinitives above.

It is necessary to know the difference between the two tenses, since
the misuse of tenses leads to a certain class of errors.

73. SEQUENCE OF INFINITIVE TENSES. The wrong tense of the infinitive
is frequently used. The following rules should be observed:

1. If the action referred to by the infinitive is of the same time
or of later time than that indicated by the predicate verb, the
PRESENT INFINITIVE should be used.

2. When the action referred to by the infinitive is regarded as
completed at the time indicated by the predicate verb, the PERFECT
INFINITIVE should be used.

Examine the following examples:

Wrong: _I should have liked to have gone._

Right: _I should have liked to go_ (same or later time).

Right: _I should like to have gone_ (earlier time).

Wrong: _It was bad to have been discovered._

Right: _It is bad to have been discovered_ (earlier time).

Right: _It was bad to be discovered_ (same or later time).

Right: _She did not believe her son to have committed the crime_
(earlier time).

Right: _When he died, he believed himself to have been defeated
for the office_ (earlier time.)

EXERCISE 54

_In the following sentences choose the proper form from those
italicized:_

1. I was sorry _to have heard to hear_ of John's death.
2. Should you have been willing _to go to have gone_ with us?
3. The game was intended _to be played to have been played_
yesterday.
4. I intended _to write to have written_ long ago.
5. He wished _to have met to meet_ you.
6. I should have liked _to meet to have me