jack said:
http://www.geocities.com/gwyni_99/prfgreen.html
Walter had been taking Spanish lessons since he was in high school, so he should have been pretty good. <-- i don't get this? "since he was in high school" isn't that a unspecific time? shouldn't they use "have"? If i used have what difference would it make?
You have to look at the rest of the paragraph. It sounds as if the entire story is set in the past. Once one is in the past, then things that occurred before the time of the story, would be in the past perfect. If the story were in the present, we would say, "Walter has been taking Spanish lessons since he was in high school, so he should be pretty good."
Now, imagine that someone is talking about their friend Walter in the past tense.
Walter I went to Mexico ten years ago. We were walking down the street looking for a place to eat. Walter walked up to a guy on the street and spoke Spanish to the man. The man became very angry and Walter was shocked. After all, Walter had been taking Spanish lessons since he was in high school and he should have been pretty good. As it turned out, instead of asking about a restaurant, Walter had mistakenly propositioned the man.
The entire story is set a time ten years ago. Everything was ten years ago, except Walter's Spanish lessons, which began a time prior to ten years ago. So the "has been taking" became "had been taking" and the "should be pretty good" became "should have been pretty good".
Same with this sentence, i don't see the different events
The man had been waiting to see a doctor for two hours.
Can you explain why did they use had? and not have?
Again, the story is set in the past, and the man began waiting before the time reference of the story.