Question

He (forget )...............my name ,so I reminded him

Answer 1

He forgot my name, so I reminded him.

Answer 2

He had forgotten my name, so I reminded him. -This is the answer.

About past perfect tense:

• Past is a verb tense used for a past activity or past state of being.
• Past perfect tense is used when we talk about something that had happened even before a past. (Eg): The dog had bitten (past perfect)the sofa even before he arrived (past tense).
• Past perfect is used to show that something had happened before another action in the past.
• Past Perfect is formed by 'had + past participle'
• (Eg); 'had done', 'had written', 'had opened'. (Done, written, opened are all past participles of the verbs).
• In the sentence given, they talk about a past happening -'I reminded him'.
• But forgetting the name must have happened even before it, only because if it the name is reminded. So it takes past perfect tense -'had forgotten'.
• Therefore the answer is: He had forgotten my name, so I reminded him.