perfectives

In English, the perfective is often formed with the auxiliary 'have' and a past participle.

用法提示：这里的 perfective 是名词，表示一种时态或体。

The teacher explained that the perfective focuses on the completion of an action.

用法提示：perfective 指代完成时这一语法概念。

Linguists distinguish between perfective and imperfective aspects in many languages.

用法提示：perfective 作为名词，表示完成体。