E. Le is used to ask or answer general questions about who did something without requesting specific information about quantity, duration and so on. For example, the speaker would ask who bought books instead of who bought three books, or who drank wine instead of who drank two glasses of wine.


5.1     A:      Shéi mǎi shū le?  


                   Who bought books?


          B:      mǎi shū le.  


                   I did. (I bought books.)


5.2     A:      Shéi Zhōngguó le?  


                   Who went to China?


          B:      Zhōngguó le.  


He did. (He went to China.)


Note that if specific information is sought, the sentence must use verb-suffix le instead of the sentence-end le.


5.3     A:      Shéi -le liǎng bēi jiǔ?  


                   Who drank two glasses of wine?


          B:      -le liǎng bēi jiǔ.  


                   I did. (I drank two glasses of wine.)