Which relativizers may be used in modifying clauses and phrases?

Question

If a relative clause modifies a noun or a pronoun in a main clause, then we could use relative pronouns such as that, which, who, whom, whose, and relative adjectives such as where, why.

During reading, I find that sometimes people use a non-restrictive relative clause introduced by "which" to give more information about phrases in the main clause, or comment on part of the main clause or the main clause. Please refer to the following examples. So I am wondering whether we should only use non-restrictive clauses introduced by "which" in these situations (i.e. giving more information about phrases in the main clause, commenting on part of the main clause or the main clause).

Example: 1: He likes climbing mountains, which is a good exercise.

("which is a good exercise" gives more information about "climbing mountains")

2: He said that he had never seen her before, which was not true.

("which was not true" is a comment on "he had never seen her before")

3: Tom was late, which surprised me.

("which surprised me" is a comment on "Tom was late")

Please help me. I really need your help. Thank you in advance!

Answer 1

Any of the wh- relatives except how and why may head a non-restrictive bound relative clause. (How and why are only used to head free relative clauses.) That does not head a non-restrictive bound relative clause in writing or prepared speech. You will occasionally hear that heading non-restrictive bound relatives in spontaneous speech, where the restrictive/non-restrictive distinction is not clearly drawn.

Which you use depends on the gender (person/non-person) of the referent and, in the case of who/whom/whose, on the syntactic role of the pronoun.

I've just bought the new book by Neal Stephenson, which I look forward to reading tonight. ... The referent is the new book by Neal Stephenson, not a person.

I've just bought the new book by Neal Stephenson, who is an author I enjoy tremendously. ... The referent is Neal Stephenson, a person, and the subject of enjoy.

I've just bought the new book by Neal Stephenson, whose works I always enjoy. ... The referent is Neal Stephenson, a person, and the possessor of works.

I've just bought the new book by Neal Stephenson, whom I admire greatly. ... The referent is Neal Stephenson, a person, and the object of admire.

You will occasionally hear that heading non-restrictive bound relatives in spontaneous speech, where the restrictive/non-restrictive distinction is not clearly drawn. ... The referent is spontaneous speech, the 'location' of this phenomenon.

This ambiguity is apparent at pauses, when the speaker experiences difficulty projecting the next burst of speech. ... The referent is pauses, the 'occasion' for this phenomenon.