“Which” and “that” are sneaky little fellows. They’re both used to refer to places, things, and animals, but they’re not interchangeable. In fact, most people use them incorrectly without even realizing it.
That is a big bummer, which I now intend to remedy.
This three-minute grammar lesson will solve the puzzle of “which” versus “that” for good.
When to Use That
“That” is used to introduce (or begin) essential clauses.
After reading that sentence, you’re probably sad, because “essential clauses” sounds like something to do with Christmas presents, but you’re pretty sure it doesn’t since this is a grammar blog. So you’re stuck even deeper in the mud of ignorance. Without presents.
In that case, let me pull you out and give you the gift of knowledge.