An English conundrum – that or which?

That and which are two little words of the English language around which there is a huge amount of confusion. They are commonly misused and most native speakers treat them as interchangeable. However, there are grammatical rules regarding the use of that and which. Allow us to enlighten you with a quick grammar guide!

Defining clauses

It’s actually relatively straightforward to identify whether you should be using that or which in your sentence.

In a defining clause, use that.

In non-defining clauses, use which.

A defining clause is also known as a restrictive or essential clause. It is an addition to sentence which is essential to the meaning of the sentence. A defining clause distinguishes between one modified noun within the sentence and all others.

There are two cars parked in the garage. You should take the one that has been cleaned.

Non-defining clause

A non-defining clause does not materially change the meaning of the sentence. If the clause were to be removed from the sentence, some detail would be lost, but not the principle meaning. Non-defining clauses are usually separated from the rest of the sentence by commas.

I entered the car, which wasn’t locked, and found my missing handbag.

Sometimes, two almost identical sentences can have different meanings, and this is where the correct use of that and which becomes more important.

I entered the car, which wasn’t locked, and found my missing handbag.

I entered the car that wasn’t locked and found my missing handbag.

The first of the above sentences suggests that there was a single car and it wasn’t locked. The second sentence suggests that there was more than one car and the writer opened the only car that wasn’t locked.

Sometimes, a non-defining clause is separated from the rest of the sentence by a single comma. This is often when the clause is positioned at the end of the sentence.

I entered the car, which wasn’t locked.

Here, the fact that the car wasn’t locked is additional and unnecessary information. Thus, the use of the word which is grammatically correct.

Precision or added detail?

If you find the concept of defining and non-defining clauses confusing, then fear not! When deciding whether to use which or that, simply ask yourself whether you are lending precision to your words, or you are merely adding detail. Choose the word that for precision and the word which when adding detail.

Who or that?

There is also much confusion around when the word who should be used instead of the word that.

The lady that was driving the car was elderly.

The lady who was driving the car was elderly.

It is perfectly acceptable to use either who or that to refer to a person. However, if you are referring to an object, animal, company, organisation or group, only that will do!

Did you see the sports car that crashed by the beach?

Did you hear the dog that was barking all night?

that or which

A word to the wise

It’s incredibly easy to make mistakes when using that, which and who. So easy, that many native English speakers would struggle to explain the correct usage of these words. Translators should take care, grammatical errors concerning that, which and who may not always be noticed but they can change the meaning of your sentences. It is worth ensuring that you have chosen the right words.