the tense of the principal verb: as,
"What did you say his name _is_?"
4. The _perfect infinitive_ is properly used to denote action which is
completed at the time denoted by the principal verb: as, "I am glad _to
have seen_ Niagara Falls;" "He felt sorry _to have hurt_ your feelings."

EXCEPTION.--_Ought, must, need,_ and _should_ (in the sense of "ought")
have no distinctive form to denote past time; with these verbs present
time is denoted by putting the complementary infinitive in the present
tense, past time is denoted by putting the complementary infinitive in the
perfect tense: as, "You ought _to go_," "You ought _to have gone_;" "He
should _be_ careful," "He should _have been_ careful." A similar change
from the present to the perfect infinitive is found after _could_ and
_might_ in some of their uses: as, "I could _go_," "I could _have gone_;"
"You might _have answered_."

[80] "Foundations," pp. 93-98.
[81] This is sometimes called the "Law of the Sequence of Tenses."

EXERCISE XLVII.

_Distinguish in meaning between the following_:--

1. The house stood (has stood) twenty years.
2. The messenger came (has come).
3. He should stay (have stayed).
4. It rained (has rained) for two weeks.
5. He was believed to live (to have lived) a happy life.
6. He ought to go (to have gone).
7. He deposited (has deposited) the money in bank.
8. I am sure I could go (have gone) alone.
9. Yesterday at three o'clock I completed (had completed) my work.
10. He must be (have been) weary.
11. He appeared to be (have been) crying.
12. He need not go. He need not have gone.
13. The horse jumped (had jumped) into the field, and began (had begun) to
eat the corn.
14. Achilles is said to be (have been) buried at the foot of this hill.

EXERCISE XLVIII.

_Which of the italicized forms is right_?--

1. Where did you say Pike's Peak _is_ (_was_)?
2. I intended _to do_ (_to have done_) it yesterday.
3. Atlas _is_ (_was_) a mythical giant who was supposed _to hold_ (_to
have held_) the sky on his shoulders.
4. I do not think that any one would say that winter _is_ (_was_)
preferable to spring.
5. Cadmus was supposed _to build_ (_to have built_) Thebes.
6. Your father grieves _to hear_ (_to have heard_) of your bad conduct.
7. Would he have been willing _to go_ (_to have gone_) with you?
8. I meant _to write_ (_to have written_) yesterday.
9. He tried to learn how far it _is_ (_was_) from New York to Syra