Use of proper words: relative pronouns

Question

Q1: What is the correct one of the words "which" and "that" to use in the following sentence:

I know the man, which/that we met yesterday.

Q2: Is the word "give" and "that" correctly used in the following :

I gave him a watch, that he liked, on his birthday.

If there are mistakes in any other part of the question, please correct me.

If you have in mind what defining or non-defining relative clauses are, then this won't be difficult. 1) it's a defining one and 2) it's a non-defining one. — Alejandro, Feb 28 '16 at 11:59
Possible duplicate of “that” and “which” as relative pronoun — Glorfindel, Feb 28 '16 at 16:44

Alejandro · Accepted Answer · 2016-02-28 17:05:42Z

Relative clauses can be restrictive (or defining) and non-restrictive (or non-defining).

In defining relative clauses, we can use the relative pronouns which, where, who, whose and we can replace who, which with that. This type of clause immediately adds vital information about the noun and commas aren't used:

I know the man who/that we met yesterday.
Non-defining relative clauses add extra information about the noun, which is unnecessary for the meaning. We put the extra information between commas and the relative pronouns who, which cannot be replaced by that:

I gave him a watch, which he liked, on his birthday.

1 Answer 1