Question

As soonbasvwe reached the station,the train left(turn into negative)

Answer 1

The sentence should be "The train had left before he reached the station." The use of the past perfect tense "had left" means he reached the station after the train "had left," so using "when" is inappropriate because it implies that both occurred at the same time. Using the past perfect tense for both events is incorrect.

Answer 2

the train did not leave the station until we reached there.