Have you ever struggled with knowing when to use that and when to use which? Well struggle no longer!
The first thing we need to discuss is something called a restrictive clause. A restrictive clause is a part of the sentence that you can’t get rid of because it specifically restricts the noun. That sounds a lot more complicated than it is, so let me give you a few examples:
I went to the carnival with the girl who lives next door. –> here “who lives next door” is the restrictive clause
I went to the carnival with Sarah Jones, who lives next door –> here “who lives next door” is a non-restrictive clause
You should have noticed two things:
1. Without the information in the restrictive clause, the meaning of the sentence would change. Without it, we would be saying that I went to the carnival with a girl. It could be any girl. But with the restrictive clause, you know it was the girl who lives next door.
The information in the non-restrictive clause, on the other hand, could be left off as you already know that the girl was Sarah Jones.
2. The restrictive clause doesn’t use a comma. The non-restrictive clause does.
Restrictive Clauses = That
Now with our knowledge of restrictive and non-restrictive clauses, I can tell you that:
you use that before a restrictive clause and which before everything else
Here is an example:
Cars that are red receive more tickets. –> no commas, restrictive clause (red cars get more tickets, not all cars)
Cars, which are common in the USA, usually have four wheels. –> commas, non-restrictive clause (doesn’t matter if cars are common in the USA or not, they usually have four wheels)
One Extra Thing
A good tip is that the information that goes with which can be thrown out and your sentence will still have the same meaning. Whereas if you throw out the information that goes with that, the meaning would change. You need the that!
Ice cream, which comes in many flavours, makes a fantastic dessert. –> Ice cream makes a fantastic dessert. –> same meaning
Ice cream that comes from Italy is my favourite. –> Ice cream is my favourite. –> see how the meaning changes?