THAT vs. WHICH or WHICH vs. THAT: no matter which way you list them, these words cause a heap of mischief. I'm happy to manage that mischief by explaining how and when to use each one. So read on, my friends, and all will be explained in easy-to-understand language.
WHICH should always follow a comma, with the noun it explains placed right before it. Here's an example, with scholarship as the object noun tied to WHICH:
Ginger desperately hoped to win the scholarship, which was open to all student athletes.
Could you use THAT instead of which in the above sentence? Not without changing the sentence around, which I will do below.
THAT is used inside your main sentence (independent clause). As promised, here's the original example restated:
The scholarship that Ginger desperately hoped to win was open to all student athletes.
The 1st sentence has "Ginger" as its subject, while the 2nd sentence has "the scholarship" as its subject. In grammar terms, THAT sets off an essential (restrictive) clause, WHICH means it isn't separated by commas.
Sometimes, however, using WHICH instead of THAT can change a sentence's meaning. Here's an example:
Our dog that came from Arkansas is very energetic.
Our dog, which came from Arkansas, is very energetic.
The 1st sentence implies you own more than one dog. The 2nd sentence implies you own one dog only and it came from Arkansas.
Special grammar note: The way the 2nd sentence is constructed, "which" is part of an appositive phrase: if lifted out of the sentence, the sentence will still make sense. Without the appositive phrase, it would read, "Our dog came from Arkansas." That helps to explain why the 2nd sentence implies a single dog.
This helpful post came from a reader's question, so please, keep your questions coming!! Thank you for reading and sharing A Spoonful of Grammar.
Laura Fineberg Cooper