Today, I’d like to explain something which is very confusing for many students: when to use the past perfect tense (had/hadn’t + pp). Generally, we use this in sentences which have more than one verb and one of the actions happened before the other one. I know this is probably still confusing, so let me give you some example sentences.
I have worked at ABC Company for ten years.
I worked at XYZ Company for fifteen years.
I had worked at XYZ Company for fifteen years before I came to ABC Company.
In the second sentence, we have to use the simple past tense because there’s only one verb and it’s describing a completed action. In the third sentence, we must change it to the past perfect (had worked) because of the presence of the verb “came” in the sentence. The action of working at XYZ Company happened before coming to ABC Company, and there’s a direct connection between them, so we use the past perfect tense.
It’s important to emphasize the fact that there must be a direct relationship between the two actions in order to use the past perfect tense. If there’s not a direct relationship between them, both verbs will use the simple past tense. For example:
I studied at the library before I came home.
I watched TV after I finished my homework.
In these cases, there’s no direct connection between studying at the library and coming home or watching TV and finishing the homework; they simply happen before or after each other.
However, if we can establish a direct connection, then we can use the past perfect tense. For example:
My teacher had given me a lot of homework, so I studied at the library all day.
I bought a new computer yesterday because I had wanted one for a long time.
In these cases, the words “so” and ” because” establish a direct connection between the two ideas, so the one that happened first must be in the past perfect tense.