"That" and "Which" by Solomon Osuokam Ogbeh

Understanding the correct usage of "that" and "which" is crucial for crafting clear and precise sentences. Both words are used as relative pronouns, connecting clauses to nouns, but their usage varies based on whether the clause they introduce is restrictive or non-restrictive.

Part of Speech

"That" and "which" function as relative pronouns. A relative pronoun introduces a relative clause, which provides additional information about the noun it follows.

Restrictive vs. Non-Restrictive Clauses

• Restrictive Clauses (also known as defining clauses): These clauses are essential to the meaning of the sentence. They specify the noun being discussed, without which the sentence would lose its essential meaning. "That" is used to introduce restrictive clauses.
• Non-Restrictive Clauses (also known as non-defining clauses): These clauses add extra information to the sentence. The sentence would still be complete and retain its basic meaning even if the clause were removed. "Which" is used to introduce non-restrictive clauses.

Using "That"

"That" is used in restrictive clauses to specify the particular noun being referred to. It does not require commas to set it off from the rest of the sentence.

Examples:

1. The book that Tunde borrowed from the library is due tomorrow.
• This sentence specifies which book is due tomorrow—the one Tunde borrowed.
2. The car that Amina drives is very fuel-efficient.
• This sentence specifies which car is being described—the one Amina drives.

Using "Which"

"Which" is used in non-restrictive clauses to provide additional, non-essential information about a noun. These clauses are set off by commas.

Examples:

1. The book, which Tunde borrowed from the library, is due tomorrow.
• This sentence adds extra information about the book. The main point is that the book is due tomorrow.
2. The car, which Amina drives, is very fuel-efficient.
• This sentence adds extra information about the car. The main point is that the car is fuel-efficient.

Detailed Examples and Exercises

To help understand the difference between restrictive and non-restrictive clauses, let’s examine more examples and then practise identifying and using "that" and "which" in different contexts.

Restrictive Clause with "That":

• The house that Chinedu built is on the hill.
• This sentence specifies which house is on the hill—the one Chinedu built.
• The dress that Ngozi wore to the party was stunning.
• This sentence specifies which dress was stunning—the one Ngozi wore to the party.

Non-Restrictive Clause with "Which":

• The house, which Chinedu built, is on the hill.
• This sentence adds extra information about the house. The main point is that the house is on the hill.
• The dress, which Ngozi wore to the party, was stunning.
• This sentence adds extra information about the dress. The main point is that the dress was stunning.

Exercises

1. Identify whether the clause is restrictive or non-restrictive and choose the correct relative pronoun (that or which):
• The cake ___ you baked was delicious.
• The car, ___ has a blue bonnet, is parked outside.
• The novel ___ I am reading is very interesting.
• His laptop, ___ is quite old, still works perfectly.
2. Rewrite the following sentences, adding commas where necessary to indicate non-restrictive clauses:
• The river which flows through the village is polluted.
• The phone that I bought last week is already broken.
• My cousin who lives in Lagos is visiting us next week.
• The painting that hangs in the hallway was made by my grandmother.
3. Create sentences of your own using "that" and "which" to describe items in your classroom or home.

Conclusion

The correct use of "that" and "which" can significantly enhance clarity in writing. Remember, "that" introduces essential information with no commas, while "which" adds non-essential information and is set off by commas. Mastery of these relative pronouns will improve your writing precision and coherence, making your communication more effective.