b-inf不變動詞係咩黎?

The bare infinitive is used as the main verb after the dummy auxiliary verb do, or most modal auxiliary verbs (such as will, can, or should). So, "I will/do/can/etc. see it."
Several common verbs of perception, including see, watch, hear, feel, and sense take a direct object and a bare infinitive, where the bare infinitive indicates an action taken by the main verb's direct object. So, "I saw/watched/heard/etc. it happen." (A similar meaning can be effected by using the present participle instead: "I saw/watched/heard/etc. it happening." The difference is that the former implies that the entirety of the event was perceived, while the latter implies that part of the progress of the event was perceived.)
Similarly with several common verbs of permission or causation, including make, bid, let, and have. So, "I made/bade/let/had him do it." (However, make takes a to-infinitive in the passive voice: "I was made to do it.")
With the verb help. So, "He helped them find it."
With the word why. So, "Why reveal it?"
The bare infinitive is the dictionary form of a verb, and is generally the form of a verb that receives a definition; however, the definition itself generally uses a to-infinitive. So, "The word 'amble' means 'to walk slowly.'"
The bare infinitive form is also the present subjunctive form and the imperative form, although most grammarians do not consider uses of the present subjunctive or imperative to be uses of the bare infinitive.

2009-10-04 11:01:23 補充：
In English, the infinitive without to, as used with modal auxiliary verbs. In the sentence I must go to the store now, the verb go is a bare infinitive.

2009-10-04 11:01:42 補充：
唔明再問

2009-10-04 21:37:45 補充：
Bare-infinitive姐係"to-infintive"冇to既形態
英文入面有d動詞系跟Gerund或to-infinitive或bare-infinitive
亦都有動詞跟gerund、to-infinitive,(呢d不多說了)
跟Bare-infinitive的動詞有很多,大概可以分成幾類:

2009-10-04 21:37:54 補充：
1) 感官上 e.g. see,watch,hear,small,taste...
2) had better, would rather, can do nothing but...
3) model verbs e.g. will, would, shall, should...
4) need not, dare not, do, did, does

2009-10-06 20:14:42 補充：
　一些動詞後面可以跟帶to不定式動詞（to infinitive）或動名詞（gerund），一些時候意思一樣，但一些時候則意思不同。

　跟在一個動詞後面的帶to不定式動詞(to infinitive)，通常是用於表達意向、動向、目標等等，就是想要、準備、開始或正在做某些事情。舉例說明：

　
　

2009-10-06 20:14:56 補充：
He started to talk but no one was listening.

他開始發表言論，但沒有人在聽。

　She continued to dance even when the music had stopped.

雖然音樂已經停下，她繼續起舞。

to infinitives涉將要或在進行的行動