I don’t know how I never thought of this topic, but luckily a friend thought of it for me, so it’s being made. 😀 This is going to be a pretty short and sweet post. These words aren’t too difficult, it’s just that many people don’t know you’re not always supposed to use “that.” So let’s begin!
You use “who” when referring to a single person: “Kelly, who likes ice cream, went to the store.” Notice that the dependent clause (“who likes ice cream”) can be removed from the sentence without changing the meaning.
You use “that” when referring to a group or an inanimate object (such as a desk). For example, “I do not like that book.” Or, using a group of people: “I do not like that football team.” Those of you who have read my that vs. which post will notice “that” is not like “who” and you cannot remove it from the sentence without damaging the intent of the sentence.
Note: If you want to add additional information that CAN be removed, you use “which”: “The team, which is currently in first place, is very talented.”
So there is a bit of a gray area when it comes to non-human animate objects, particularly our pets. Some people say, “I have a cat that has gray fur.” Other people say, “I have a cat who has gray fur.” Although, technically, it should probably be “that,” many people use “who” and it’s generally accepted.
If you remember that “who” is with people and “that” is with objects, you should be–for the most part–fine. Good luck!