What's the role of 曾经 in this sentence?

Question

In this sentence:

他曾经在北京学过两年汉语。

what's the role of 曾经 ? I understand that 过 already implies that the action happened in the past.

Answer 1

曾经 is more equivalent to "once" in English as in the sentence

Once we were the best friends.

It is used to:

1. express the fact the sentence is talking about happened in the past.

2. if the predicate verb is a durative verb*, express that fact can't be experienced(经=experience) by the speaker(doesn't last) any more.
   , the speaker implies that the status is different now. In this case, it means "used to" as in the sentence "I used to be a kind man(implies now I am not)." For your example, the speaker implies that he is not studying Chinese in Bejing now.

*By "durative verb", I mean the action expreesed by that verb can last for a long time. For example, "study, like, look, be, work,feed, etc.". These verbs can be used in the progress tense in English(-ing form). Some other verbs can not, such as "hear of, see, kick, etc." You can't say " I am hearing of a terrible story", while you can say" I am listening to a terrible story".

Can someone tell me the right grammar term if I am wrong?

Answer 2

It means 'already', to add emphasis to the sentence - 'he already studied Mandarin in Beijing for two years'

Answer 3

Just as 已经 means "already" and emphasizes the sense of the completed action particle 了, 曾经 means "once" and emphasizes the sense of 过. I disagree with Bob that 曾经 means already here; in general "once" or "ever" is a better translation. I would render your sentence as "I once studied two years of Chinese in Beijing."