the Greater Nomadic Council

Today's Grammar Lesson

Per RP's request in the comments and to keep the blog from going completely dead, I will now explain the difference between "that" and "which" and restrictive and non-restrictive clauses, drawing largely from Strunk and White's Elements of Style since they explain it quite nicely. As I wrote before, "that" is used in restrictive clauses and "which" is used in non-restrictive clauses. A non-restrictive clause is a dependent clause that provides information that is not essential to the meaning. Strunk and White write:

A non-restrictive clause is one that does not serve to identify or define the antecedent noun.

The audience, which had at first been indifferent, became more and more interested.

As you can see, the sentence would still make sense were the non-restrictive clause that begins with "which" dropped. A restrictive clause, then, is one that is essential to the meaning of a sentence. As another example, here's one that a professor of mine once used:

Restrictive: The car that is in the garage belongs to my mother.

Non-restrictive: The car, which is in the garage, belongs to my mother.

In the first case, the use of a restrictive clause to designate the car implies that there is another car, perhaps in the driveway, thus requiring that the speaker specify which car is meant. In the second case, the information about the car's location is superfluous.

Of course, in everyday speech, we often use "which" rather than "that" for restrictive clauses, hence the common confusion on this topic.

On a related note, this is useful for me as I will be teaching freshman rhetoric (grammar and composition) next year. It should be painful, but instructive.