Past Perfect Tense
The past perfect tense should be used for the action that occurs first.
E.g.
1) I brushed my teeth. I left the house hurriedly.
"I brushed my teeth" occurred first, so we should write:
After I had brushed my teeth, I left the house hurriedly.
or Before I left the house hurriedly, I had brushed my teeth.
2) I did my homework. I went to bed.
Logically, "I did my homework" occurred first, so we write:
After I had done my homework, I went to bed.
or Before I went to bed, I had done my homework.
or By the time I went to bed, I had done my homework.
The past perfect tense is also used in reported speech, which we will learn tomorrow. Do pay attention!