我們注意到操作詞都是動詞的現在式或過去式，是限定動詞形式。限定動詞形式可以并只可以用于謂語動詞詞組第一動詞的位置。也就是說操作詞在句子中的位置是謂語動詞詞組第一動詞位置。

當一個句子按語法要求需要用操作詞而原句沒有操作詞時，就在謂語動詞詞組第一動詞位置加上助動詞do的現在式或過去式，使其具有操作詞。助動詞do后接原實意動詞的不帶to的不定式形式。

操作詞的語法特征如下：

1. 肯定句變否定句時否定詞not直接置于操作詞之后。

He will come tomorrow.

He will not come tomorrow.

He loved her.

He did not love her.

2. 非正式語體尤其口語中，操作詞可以和not構成縮合式。（am的縮合式ain't只用于俚語）。縮合后為重讀。注意正式語體不可用操作詞和not的縮合式。

3. 參與一般疑問句和選擇疑問句的構成：操作詞移至主語前，句末用問號，讀升調：

He is an English teacher.

Is he an English teacher (or math teacher)?

He wants to buy a car.

Does he want to buy a car (or a motorcycle)?

4. 反義問句（附尾問句）的問句部分構成：操作詞 + 人稱代詞？（前否后肯，前肯后否）

You have two children, haven’t you？（英式）/don’t you?(美式)

He won’t come, will he?

5. 有的詞項前置時（如否定副詞或only加狀語），需要部分倒裝句，就是操作詞的倒裝：

   I have never seen this before.

   Never have I seen this before.

   He had scarcely finished his dinner when she came.

   Scarcely had he finished his dinner when she came.

   We had a meeting only when necessary.

   Only when necessary did we have a meeting.

   He gets up at six o’clock every day.

   When does he get up every day? (疑問詞前置導致部分倒裝。)

   Three students were late for class.

   How many students were late for class? (疑問詞本身就位于主語前，并無前置，所以不倒裝。)

（部分倒裝句（即操作詞的倒裝）是由前置導致的結果，前置的內容是信息中心。

完全倒裝句（實意動詞的倒裝）是后移帶來的結果，信息中心在句末。）