presnt perfect continuous

有四個法則:
1. 已經開始咗GE
2.未完成GE
3.將會繼續
4.時間GE 長度

E.g I am waiting for half an hour but no trains have arrived yet.
<<個意思係1.我已經一早等緊2. 我未等到3. 我會繼續等4. 等咗有個半鐘了

重點:
a. 剛才四個法則
b. 一定是在現在式中出現(eg. today, this week , thie evening etc)

E.g We have been learning English sentence structures these week.These course are very interesting.
<<意思係a 1 我一早緊 2 我未學完 3 我會繼續學 4 已經學咗幾個星期 B 在現在這段時間中

2009-02-17 13:14:45 補充：
I am waiting for half an hour but no trains have arrived yet.<<打錯了
是I have been waiting for half an hour but no trains have arrived yet.

Present Perfect Continuous tense
現在完成進行式

己經發生咗同繼續發生緊的。

例："have been walking"。
I have been walking home for half an hour.
我己經行咗半個鐘，依家重行緊返屋企。