动词在什么情况下得变ing形式?现在进行时除外,请详细点,要有例句,答得好我还会加分

介词后面 如 look forward to doing， to是介词
固定词组 如 feel like doing
表示名词意义 如 go fishing

我简单点回答吧
现在进行时 am/is/are doing           He is playing now
过去进行时 was/were doing           He was playing football yesterday
介词之后  for/with/in/on + doing     This book is for reading
固定词组 spend...doing                 We spent four days making this.
动名词 I would appreciate your calling back this afternoon. 
V-ing 短语作主语   Listening to music is my favorite
V-ing 作伴随状语  He left alone,taking his luggages.




大概就是这些