现在完成时时间状语：表示目前已完成的动作，强调对现在的影响。时间是算到你说话的时候为止，而且现在完成时有一些标志性的时间状语：
1、for+时间段；I have learned English for ten years。
2、常见的副词：lately；recently, just，up to now, till now，so far, these days。
in the past few years/months/weeks/days。
3、注意：for+时间段；since+时间点。
They have lived in Beijing for five years。
They have lived in Beijing since l995。
温馨提示：
