had worked; worked

[Stieizc]

I saw this sentence:
He has worked in this radio factory for ten years. But before he did the job he had worked as a construction worker for five years.

I think "worked" is better than "had worked" in this sentence, or at least they are interchangeable. Am I right?

 

[chamyto]

I think that both may be possible, but when I studied English at school, I was taught that with the preposition for meaning time the Perfect tense is more appropriate.

 

[a little edgy]

They are interchangeable in this situation because the phrase "before he did the job" makes clear that we are talking about the years before he came to the radio factory. The past perfect tense (had worked) is entirely acceptable but is not required. In casual speech and writing, the simple past tense (worked) may be more common simply because it's shorter.

 

[Stieizc]

I asked my teacher, she said that "worked" happened earlier than "did", so I must use "had worked" here. Is that right?