Personal Pronouns and Complement of Duration
There is a structure  [S V O + V 了 + CoD*] (repeat the same verb)


For example: "我吃晚飯" (I eat dinner);  "我等我父親"(I wait for my father)

Put it in [S V O + V 了 + CoD*] structure

"我吃晚飯吃了一小時" 

"我等我父親等了一小時" 

Of course personal pronouns can be objects (e,g. 我等他等了一小時 ), but the structure is not limited to just personal pronouns-- It can use any noun or noun phrase 


  The structure [S V 了/过 + CoD*] Can always followed by an object


Example:

我學了/过三年(的)英語 - 英語 is the object

我畫了/过一整天(的)街景 - 街景 is the object

'的' is optional