'the past tense' vs 'the past perfect tense'

He had been living in L.A. for five years when I met him.
I lived in China for three years when I was a child.

Is "He had lived in L.A. for five years when I met him" wrong? I'd like to know whether it would be also acceptable.

lucas21cIs "He had lived in L.A. for five years when I met him" wrong?

No. But the usual conjunction would be before:
He had lived in L.A. for five years before I met him.

"When" indicates an interruption of an action, and the best verb form for that is the continuous.

My textbooks says, 'the perfect tense' doesn't match to 'when-clause'. So, according to it, #1 should be "He lived in L.A. for five years when I met him", like #2. Could you tell me what the difference is between #1 and #2? I can't get why #1 takes the perfect form or the perfect progressive form while #2 takes the past form though their grammatic structures are the same as each other.

lucas21c, according to it, #1 should be "He lived in L.A. for five years when I met him",

No. That is not correct.

The past perfect continuous is fine with a "when clause".

The simple past (he lived) is for a completed event. The adverb phrase "for five years" is a duration of time. It not correct with the when-clause (one point in t

According to you, "He lived in L.A. for five years when he was a child" is fine while "He lived in L.A. for five years when I met him" is worng, right? If so, could you tell me why "He lived in L.A. for five years when he was a child" takes the simple past form though "for five years" also means a duration of time?

"He lived in L.A. for five years when he was a child." is correct. The past tense can be used like this, for example, the following are correct:

I lived in L.A. in 1990. (A specific time in the past is indicated.)

I lived in L.A. for three years. (A continuous time period in the past in indicated.)

I lived in L.A. while working as a flight attendant. (A continuous ti