present prefect continuous tense同present continuous tense的分別

現在完成進行式 (present prefect continuous tense ) : have/has + been + Ving 用來強調'動作還是持續進行的' 現在完成進行式不僅可以強調動作的持續性，它也暗示了，動作在未來也可能持續下去。
My brother has been palying the computer games. (有可能是 他從昨晚玩電玩到現在，如此 持續而且進行的動作)

現在完成式 (present prefect tense) have/has + p.p + 一段時間 (最常看到FOR 和SINCE + 時間)
I have learned English for years. 我學習英文好多年了。
He has collected stamps since he was 7. 他從七歲就開始蒐集郵票了。 (從7歲~現在)

現在進行式 (The Present Continuous Tense) am /is /are + Ving
1. 表示說話時正在發生的事情
　e.g. I am doing my homework Now.
What is she doing at now ?
2. 表示將會發生的事情．
e.g. I am going to have dinner with my friends tomorrow.
He is going to the cinema this evening.

hope it can help you.
http://www.englishpage.com/verbpage/simplefuture.html