Many ESL students have problems with the past perfect tense simply because they don’t know how to use it. The past perfect is perhaps the most overrated tenses in English. In most cases, we can express the same idea using a simple past tense.
Native speakers do not always use the past perfect tense. They are more likely to use a time conjunction like before or after to show which action occurred first. ESL learners, on the other hand, have been taught that the past perfect tense must be used to refer to the earlier of two past actions.
Study the following sentences. Strict grammarians will argue that the past perfect tense must be used in the following sentences. However, native speakers are more likely to prefer the simple past forms.
He chose the wrong course of action because he didn’t think it through.
He chose the wrong course of action because he hadn’t thought it through.
Ask any native speaker and they would tell you that both of these sentences are grammatically correct. However, you can consider using the past perfect tense in this case because it would make your writing clearer.
Note that there is no need to use the past perfect tense in sentences connected by a time conjunction like after or before. That is because the conjunction itself makes it clear which action occurred first. Study the following sentences. The past perfect tense is unnecessary in them.
I visited Japan after I watched a program on TV.
I visited Japan after I had watched a program on TV.
The patient died before the doctor arrived.
The patient had died before the doctor arrived.