main verb

Here have is the auxiliary verb and completed is the main verb; have completed is the present perfect tense.

在这里have是辅助动词而completed是主要动词，have completed是现在完成时。

Perfect infinitive means the action happed before the main verb.

完成不定式表示动作发生于主要动词之前.

You normally put adverbials of manner, place, and time after the main verb.

方式状语, 地点状语和时间状语通常都置于主动词之后.

Future infinitive means the action will happen after the main verb.

未来不定式表示动作发生于主要动词之后.

You usually put adverbials of frequency, probability, and duration in front of the main verb.

表示频率, 可能性和持续性的状语一般放在主动词之前.

When a sentence has an auxiliary verb and a main verb, it is usual to put adverbs between them.

当句子中有一个辅助动词和一个主要动词，副词经常被放在两个动词之间。

If the main verb is in the past tense, the imperfect will be translated as a past.

（拉丁文）主要子句的动词为过去式，则（拉丁文）附属子句的未完成式动词要译成英文的过去式。