i have seen many sentences from books or dictionaries,
sometime, when they use "past perfect" sentence, they didnt indicate " had been" was happened before soemthings else.
for ex:explorers going where no man had trod before.
so, "had trod" before "when"
(according to grammar rule: when you use past perfect it's taking about something happened before somthing else in the past , right? but the sentence
above dosn't give any sense of "past of past" this sentence seem like simple past.)
sorry,I had the impression you were talking about a quote from the past,like a sentence from a book of history or the like...If these explorers are just planning to go, but havenīt actually gone, then it should be explorers going where no man has trod before.
i found this sentence in an electric dictionary, it's only given that much of clue,
so, i am confusing it. but it said: "no man had trod"
The text must be referring to people in the past who went somewhere where no-one had been before. For example, when a man walked on the moon (which happened for the first time many years ago), he was walking where "no-ne had trod before". So the past perfect tense is correct for a past event which happened before another past event.