For the longest time, as I try to think a sentence, the word "which" always confuses me.
Example:
"I am British, which is the reason I can speak it so well."
or
"I am British, which it's the reason I can speak it so well."
Another example
"I love him, which is the reason I'm going to marry him."
or
"I love him, which it's the reason I'm going to marry him."
Which one is correct? And I can put a subject after which? Can someone give me a proper explanation on this, because I keep not getting it.
Ordinarily, we think of relative pronouns as having a definite, limited antecedent in the primary clause:
My brother, who was in France at the time, had to take the first flight out. who = brother
I sent an email to the new people whom you assigned to the group. whom = people
The antecedent of which, however, can be the entire primary clause:
He wanted to go shopping in the middle of a blizzard, which I thought was an idiotic idea.
She couldn't resist buying a Great Dane puppy, which irritated her husband no end.
The blizzard was no one's idea, and while the puppy may have irritated the husband or not, it was his wife's buying it he found distressing.
In this construction, which is always the grammatical subject of its clause and its antecedent the primary clause preceding it.
In your examples:
*I am British, which it's why I speak English so well.
*I love him, which it's the reason I'm going to marry him.
You are attempting for some reason to add a second subject it, which results in an ungrammatical, highly non-idiomatic sentence. (This sentence uses which with a whole clause antecedent.)
As someone commented, "British" is a nationality, not a language.
It's a rather odd construction, but a sentence may be the antecedent for the interpretation of the relative pronoun "which" in English. McCawley describes a relative clause with such a relative pronoun as an appositive relative clause attached as an "adposit" to the sentence which is the antecedent of "which". See The Syntactic Phenomena of English.
"I am British, which is the reason I can speak it so well."
or
"I am British, which it's the reason I can speak it so well."
"I love him, which is the reason I'm going to marry him."
or
"I love him, which it's the reason I'm going to marry him."
The answers, which are highlighted in bold, are correct. (It would have also been incorrect to say "which they are highlighted") This is because "Which" serves as a subject pronoun as well as the beginning of a subordinate clause.
It is always incorrect to say "Which IT'S" or "which they are."
Please note this has nothing in common with the usage of "Which" as an adjective, i.e. "Which book do you want?" where which serves as an adjective...
