事故前他能够跳舞，有时态的变化。

He had been able to dance before the accident.

youdao

不定式可以带宾语或状语构成不定式短语，没有人称和数的变化，但有时态和语态的变化。

Infinitive form can take object or adverbial infinitive phrase, there is no person and number of changes, but sometimes tense and voice changes.

youdao

从句法层面上看，英语动词有时态变化，名词有数的变化，而汉语则没有这些变化；

Syntactically, English is a synthetic language, with ample variations in terms of tense, aspect, number and case.

youdao

只好，不得不（客观的必须，有时态人称变化）

Without help, I had to do it myself.

youdao

只好，不得不（客观的必须，有时态人称变化）

Without help, I had to do it myself.

youdao