(1) …only the most expensive exercise bicycle will help improve his body, … (Passage A, Unit 5)
(2) Kress’s program helps patients to change their spending habits… (Passage A, Unit 5)
上述两例中都包含动词help，第(1)句中help后用的是不带to的不定式，而第(2)句中help后用的是带to的不定式。
英语中的不定式 (infinitives) 可分为带to不定式 (to-infinitives) 和不带to不定式 (bare infinitives)。带to不定式是常用的形式，但有时需要用不带to的不定式。
众所周知，不带to的不定式常用于情态动词之后。除此之外，它还可用在一些动词之后作宾语补足语 (object complement)。这些动词包括let, make, have, see, watch, notice, hear, listen to, feel等。例如：
My mum wouldn’t let me go out.
Our teacher often lets us speak freely in the class.
The pain made her cry out.
Their manager often makes them work overtime.
I’ll have my son help you with your English.
He had Peter find him a house.
I saw him leave the office.
Did you see anyone open the box?
He watched the bus stop and start moving again.
The parents watched their son make a toy plane.
She noticed a boy go into the room.
The nurse noticed that the patient go out of the hospital.
I often heard her sing.
I heard him say that last Monday.
The little girl likes to listen to me play the piano.
He felt something touch his foot.
动词help之后或help +宾语之后既可用带to的不定式，也可用不带to的不定式。例如：
Our friends helped us (to) move the piano.
This medicine will help you (to) stop smoking.
I helped the old man (to) carry the heavy bag.
当help后面有一个较长的名词词组作宾语时，通常用带to的不定式。例如：
She helped the little children sitting at the back of the classroom to pass the chairs out.
I helped the student who has difficulty in English to improve his English.
请提示学生注意，当上面所列的动词用于被动语态时，必须用带to的不定式。例如：
He was heard to say that.
The old man was helped to carry the heavy bag.
此外，不带to的不定式还可用于why引导的问句中。例如：
Why worry about such unimportant things?
Why waste so much money?
Why not do it right away?
Why not let him have a chance?
不带to的不定式语法
»