‘Which vs That’ is an area which confuses many students. This is a commonly tested area in standardized exams. People often use the two interchangeably in everyday conversations. However, both these words have specific uses and mastering them will stand you in good stead for your exam.
‘That’ is used for a restrictive clause while ‘which’ is used for a non-restrictive clause. A restrictive clause is important to the meaning of the sentence and the meaning will be affected if it is removed from the sentence. On the other hand, a non-restrictive clause only provides additional information regarding the sentence and removing it has no affect on the meaning of the sentence.
Cars that don’t have airbags are unsafe to drive in.
My home, which has two bedrooms, is located in Chicago.
If you interchange ‘which’ and ‘that’, it can completely change the meaning of the sentence.
My iPhone that is red in colour is three years old.
My iPhone, which is red in colour, is three years old.
The first sentence implies that I have many iPhones and the red one among them is three years old. Moreover, if we remove the restrictive clause, the reader will not know which one of my iPhones is three years old. The second sentence simply informs the reader that I have one iPhone which is red in colour and is three years old. If you remove the non-restrictive clause, there is no ambiguity regarding the iPhone.
You should also pay close attention to commas. Typically, non-restrictive clauses are separated by the noun through commas. In the second statement about the iPhone, observe the use of comma before which. Sometimes, commas themselves can tell you whether a particular clause is restrictive or not.
Remember the golden rule – When any information is essential to the meaning of the sentence, use ‘that’. When any information is not necessary for the sentence and can be removed without changing the original meaning of the sentence, use ‘which’.
You may also be interested in: Subject-Verb Agreement