Usage of 'that' and 'which' often causes confusion. Why so? Go through the rule that differentiates the two:
That: That should be used to introduce a restrictive clause.
Which: Which should be used to introduce a non-restrictive or parenthetical clause?
Easy-peas right? Well, not quite. Let's break it down and make it into something which is easier for you to digest.
Usage of 'That':
Definition of a restrictive clause: A restrictive clause is an element of the sentence that cannot be deleted, because it restricts the noun. For example: Issues that concern the minorities cannot be ignored.
Usage of 'Which':
If a restrictive clause could not be left out of the sentence, a non-restrictive clause is its exact opposite and can be left out without changing the meaning of a sentence. Non-restrictive clauses are either in brackets or have a comma before and after them (or only before them if they come at the end of a sentence).
- *Alphanso mangoes, which are grown in 5 countries, are the juiciest variety of mangoes.
- *There was a tsunami in Japan, which is horrible news to be honest.
In both the sentences above, the fragment in 'bold' can be easily left.
'That' versus 'Which': Key Learning
In essence, if you can remove 'which' from a sentence and the meaning of the sentence is not harmed, that sentence will take a 'which' only. In case the meaning is harmed without 'that' fragment, you need to use 'that'.
Verbal Preparation Series