This was when? (這是什麼時候的事情？)

This was when? Recently, couple weeks.

This was when? Recently, couple weeks. (這是什麼時候的事情？ 最近，幾週前。)

參考資訊：

https://m.youtube.com/watch?v=EVoHXoGa0nU

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"A couple of weeks" is correct.

But, in spoken English we sometimes don't say "of". 

So "a couple weeks" is the informal or spoken way of saying "a couple of weeks"

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