8-Infinitive不定式结构

Note: help to do and help do are both acceptable.
A test item in TEM 4

"It seems that she was there at the conference." The sentence means that ____. A. she seems to be there at the conference. B. she seemed to be there at the conference. C. she seems to have been there at the conference. D. she seemed to being there at the conference. (2009)
Infinitive ―to‖ or preposition ―to‖?



Distinguish infinitive ―to‖ & preposition ―to‖ —— If ―to‖ can be followed by a noun or noun equivalent, it proves to be a preposition. Otherwise, it is an infinitive sign. The following are some examples of the collocations in which the item ―to‖ is preposition, not an infinitive sign. A) verb + preposition ―to‖, e.g. confess to attest to contribute to refer to agree to bow to object to submit to stick to adhere to pertain to take to yield to attend to resort to come to relate to amount to react to consent to … When it comes to belling the cat, the mice have nothing to say. He will not submit to being separated from her. Keeping what belongs to others amounts to stealing.
Past action/event
The forms of infinitive
Active to do passive to be done to have been done —— ——
Perfective Progressive Perfective Progressive
to have done to be doing to have been doing
Notes on the use of ―to‖

Infinitive ―to‖ used alone —— To avoid repetition, use ―to‖ alone, common in informal style, e.g. You may go if you want to. But the base verb should be retained if it is be or have,
as a waitress. Used in some fixed combinations: let go/fly/slip/fall, make do, make believe…, e.g. He did all that just to make believe. We don’t have time for lunch, but we made do with sandwiches.


Grammatical forms of infinitive

Hale Waihona Puke Used in ― causative verb + object‖, like make, let, have.. functioning as object complement, e.g. The boss made them work late on Saturday. I won’t let you go before lunch. The teacher had us read silently. But when turned into passive, to-infinitive is used instead, e.g. They were made to work late on Saturday.
Grammatical forms of infinitive





See more examples of bare infinitive: They can do nothing but/except wait for rescue. Cf: There’s no choice but/except to wait for rescue. Why ask me? Why not ask him? But: What to do? How to do? When to do? Why to do? Go post a letter for me. Try eat a little. Try help him.
Grammatical forms of infinitive

Bare infinitive following modal idioms such as: would



rather, would rather… than, would sooner, would as soon, may/might as well, cannot but…, e.g. He would rather listen to others than talk himself. Since it’s a fine day, we might as well walk. Rather than cause trouble, he left. Sooner than marry that man, she would earn her living
Grammatical forms of infinitive



2) To-infinitive & bare infinitive----infinitive is usually accompanied by ―to‖, but sometimes without ―to‖ (bare infinitive): Question: Under what circumstances should we use bare infinitive? When following modals, bare infinitive is used. But need & dare may be used in to-infinitive form. Does she dare to go there alone? Do we need to pay for the meal? Following semi-auxiliaries, bare infinitive is used, e.g. You’d better not go out. I happened to meet Mary on the way to the library.
Grammatical forms of infinitive





Used in ― sense verb + object‖, like see, hear, observe, notice, feel, watch, look at, listen to… also as object complement, e.g. I felt the house shake. I saw him walk out the room. I don’t like listening to other people talk. But when turned into passive, to-infinitive is used instead, e.g. He was seen to walk out the room.
e.g.



Aren’t you the manager? No, I don’t want to be. He hasn’t finished yet. Well, he ought to have. Sometimes the whole infinitive-clause can be omitted, e.g. You’ll make it if you try (to). I’d like to travel to Guilin, but I haven’t got the money (to).
Notes on the use of ―to‖




Ellipsis of the infinitive ―to‖ —— The second ―to‖ can be omitted when two infinitives are coordinated by and or or, e.g. I wish to buy a villa and have it decorated in my favorite style. But never omit ―to‖ when the infinitives have a contrastive meaning, e.g. To be or not to be, that is a question. Nor can ―to‖ be omitted when the infinitives cooccur in a parallel construction, e.g. The students must learn to read extensively, to analyze what he reads and to summarize the main points presented.
Infinitive

Infinitive, -ing participle and –ed participle all fall into the non-finite forms of verbs.
Grammatical forms of infinitive






1) Grammatical forms---- infinitive has no tense distinction, nor person or number contrasts. But they can be passive and take the simple, progressive, perfective and perfective progressive forms, e.g. The boy always hopes to be praised by his teacher. I have nothing to regret for. She had no need to be worrying. He is believed to have visited every province of China. The president was reported to have been flying across the Atlantic. Question: How to form a negative infinitive? A negative infinitive is formed by adding not or never immediately before the infinitive to: He promised never to do anything like that again. Mary advised me not to lend him any money.