ココネ なう。

13. The infinitive may occur either with or without a proclitic *1 particle. *2 This particle is written to, and pronounced [tu] before a vowel, [to], sometimes [tu], before a consonant. The infinitive without to is known as the PLAIN INFINITIVE.

14. The plain infinitive is only used in a verbal, never in a nominal function. In cases where other languages use a plain infinitive as the subject, object or nominal predicate of a sentence, English uses either an infinitive with to or a gerund.

　To know him is to like him.
　Do you like swimming? (Cf. 68 ff.)

15. The plain infinitive is used either by itself, or in combination with another verb. The latter use, which is the commonest, will be discussed first.

16. The plain infinitive is used:

　a. with can/could, may/might, must, shall/should, will/would
　(cf.6, 11 & 149 ff.).
　　Tell him he may go home.
　　She should have been more careful.
　　Will you open another window?

　b. with to dare and to need (cf. 7 and 203 if.), chiefly in negative and interrogative sentences:
　　How dare you come here ?
　　He need not return the letter.

　c. with to do (cf. 8 and 194 ff.) when used as an auxiliary of emphasis or periphrasis.
　　Oh, do tell us what has happened.
　　She did not seem to notice us.
　　Don't you think he is awfully clever?

　d. with had better, had best (rare), had rather, had sooner.
　　Had not [hædn(t)] we better stop now?
　　I'd [aid] rather go on, if you don't mind.
　　I'd sooner stay where I am.

　1.I'd rather and I'd sooner also serve as contracted forms of I would rather and I would sooner.
　The phrases with would sometimes occur in print, though those with had are commoner.
　　In somewhat archaic English we also find
　I would as lief (or: I had as lief, cf. COD) (lief = gladly, willingly).
　The phrase is mostly used to repudiate a suggestion:
　　She cannot abide him, and would as lief marry a seal. *3