我簡(jiǎn)單點(diǎn)回答吧
現(xiàn)在進(jìn)行時(shí) am/is/are doing           He is playing now
過(guò)去進(jìn)行時(shí) was/were doing           He was playing football yesterday
介詞之后  for/with/in/on + doing     This book is for reading
固定詞組 spend...doing                 We spent four days making this.
動(dòng)名詞 I would appreciate your calling back this afternoon. 
V-ing 短語(yǔ)作主語(yǔ)   Listening to music is my favorite
V-ing 作伴隨狀語(yǔ)  He left alone,taking his luggages.




大概就是這些