V. Aspect particle le了 and modal particle le了used together without a quantified object or duration between them indicates that the action has been completed. Such a usage is the same in meaning and function as one that takes only the modal particle le了at the end of the sentence.

 

          Wǒ kàn-le shū le. = Wǒ kàn shū le. (Kàn is stressed.)  

          我看了书了。  = 我看书了。

I’ve read the book.