1、现在完成时表示从过去持续到现在的动作或状态,此时通常与由since或for引导的时间状语连用,例如：I have waited here since three o'clock.我从3点钟就在这里等.
I have waited here for three hours.我在这里等了三个小时了.
2、现在完成时表示过去发生的对现在有影响的动作,有时可以和already,before,ever,just,lately,never,recently,yet等一些所指时间不具体的时间状语连用,如：
I have lost my key.我把钥匙丢了.
Have you ever been to Australia?你去过澳大利亚吗?
有时现在完成时也和now,today,this morning,this week,this year等表示现在的时间连用,例如：
I havent seen him today.我今天没见过他.
They have produced five films this year.他们今年拍了五部电影.
3、现在完成时在时间和条件状语从句中表示将来完成的动作,例如：I will come this evening if the rainhas stopped by then.如果晚上雨停的话我就来.
