Post by Lazypierrot
I found the following sentence;
Learners of both spoken and signed languages can produce their own
appropriate meaningful sentences that differ greatly from sentences to
which they "had" previously been exposed.
I wonder if the "had" in "had previously been exposed" should rather be
"have" instead. Is it grammatical to use "had" in the above sentence? If
so, I would like to know why.
No, it is not.
The past tense of the auxiliary makes the "past perfect" tense: the form
identifies an act that was complete by some specified or implied time now
past. "By the end of the Civil War, most of the region had been
Using "have" as the auxiliary makes the "present perfect" tense; that is
used to describe action which began in the past but still continues, or
that is at least linked to the present.
One text puts it this way:
This form refers to time now past but in some way connected with the
present. In the afternoon, we can say "I have bought a new hat this
afternoon," but if we report this same purchase in the evening, we say
"I bought a new hat this afternoon."
In the original query, the phrase "can produce" is present tense, so the
"had been exposed" is inappropriate. (Had the original been describing
something in the past, and thus used "could" instead of "can" and
"differed" instead of "differ", "had" would work; but that implies that
context external to the sentence had identified that past time being