1 现在完成时（I have done）

开始于过去并持续到现在（也许还会一直持续下去）的动作。

I haven't see her this morning .(直到此刻还没见过他，此刻还是上午)

总是与现在有着亲密切的联系，表示过去的动作对现在的影响。

"Where is your key ?" " I don't know .I have lost it ." =(i don't have it now )

注意gone（to） 与 been （to）的区别

James is on holiday .He has gone to Italy (=he is there now or on his way there .)
Jane is back home now .She has been to Italy .(she has now come back )

2 现在完成进行时 （I have been doing ）

表示不久之前结束的或者刚刚结束的动作，这个动作与现在有关联

Why are yours clothes so dirty ? What have you been doing ？（your clothes are dirty now ）

表示某个动作仍在进行或者刚刚停止,尤其是与how long ,for ,since 连用时。

It began raining two hours ago and it is still raining .
How long has it been raining ?
It has been raining for tow hours.