完成体和未完成体之间的对立见于许多斯拉夫语。

The aspectual contrast between perfective and imperfective is found in many Slavic languages.

youdao

但是，由于现在完成进行体还带有进行体的持续性、暂时性和未完成性的含义，有时就不可以与现在完成体互换使用。比较。

T here are cases, however, where these two forms are not interchangeable in that the present perfective progressive has also the meanings of continuousness, temporariness and incompleteness .

youdao