@WBYeats,
Quote:-This is the first time (that) I've been to London.
1. Can VE BEEN change to WENT/HAD BEEN?
2. If the present perfect tense must be used in that construction, which one can I say?:
It depends on the TIME of the event.
e.g.
This IS the first time I've been to London
This WAS the first time I'd (I HAD) been to London
so
Quote:-You are the first/second/third American who is/has been able to tell me where Nagasaki is.
-You are the first American who has been able to tell me where Nagasaki is.
(writing about the present (You are...), but talking about past events (who has been able...)