现在完成时

表示动作发生在过去，完成在过去，但强调与现在情况仍有联系，其结果或影响仍存在。现在完成时有一些标志性的时间状语：

考点一：for + 时间段；since + 时间点

They have lived in Beijing for five years.

They have lived in Beijing since 1995.

I have learned English for ten years.

考点二：常见的不确定的时间状语：lately; recently, just, already, yet, up to now; till now; so far, these days,

Has it stopped raining yet ?

考点三：在表示“最近几世纪/ 年/ 月以来……”时间状语中，谓语动词用现在完成时。

in the past few years/months/weeks/days；over the past few years; during the last three months; for the last few centuries, through centuries; throughout history 等