That vs. Which

Grammar Notes:

When should a person use “that” or “which” in a sentence?  What is the difference?  Well, they are both tools to introduce descriptive clauses that reference an object.  The decision whether to use “which” or “that” will rest on the type of clause:  restrictive or non-restrictive.

The words restrictive and non-restrictive may sound confusing, but the concept is not difficult.  If a restrictive clause is removed, the meaning of the sentence will change.

Find the dog that likes Beefy Miracle Dog Food. (restrictive)
He picked up a book, which had a red cover.  (non-restrictive)

Note: both “that” and “which” should immediately follow the object the clause is referencing, and a comma will almost always precede the word “which”.

Tip:  generally, we will see the article “a” along with non-restrictive clauses, but we will see “the” associated with restrictive clauses.

Be aware who or whom should be used when referring to people.

WRONG:   Where is the person that took the tip?
Right:         John is the one who ate the cake.

That should introduce a restrictive clause; which should introduce a non-restrictive clause (a clause that can be left out without changing the meaning of a sentence)