Student or Learner
ENGLISH PAGE - Past Perfect
USE 2 Duration Before Something in the Past (Non-Continuous Verbs)
With Non-Continuous Verbs and some non-continuous uses of Mixed Verbs, we use the Past Perfect to show that something started in the past and continued up until another action in the past.
-We had had that car for ten years before it broke down. (It is OK, I understood it)
However I couldn't understand this part:
Although the above use of Past Perfect is normally limited to Non-Continuous Verbs and non-continuous uses of Mixed Verbs, the words "live," "work," "teach," and "study" are sometimes used in this way even though they are NOT Non-Continuous Verbs.
1- When you came in the room, I had studied English for six hours. (Is it ambiguous? Does it mean that the studying that had started in the past continued up to another action - when you came in the room- or before you came in the room I had studied English for six hours. I completed it. Maybe I begun to read something else?)
2- When you came in the room, I had already studied English for six hours. For this reason you saw me watching TV.