That vs. Which
Adding a modifying clause to identify which noun
An Identifying vs. Nonidentifying Relative Clause
| AN IDENTIFYING RELATIVE CLAUSE — THAT / WHICH | A NONIDENTIFYING RELATIVE CLAUSE — WHICH |
|---|---|
An identifying (restrictive) relative clause adds information or narrows the noun to a specific one, group or lot. The clause helps by telling us which one, where or when. The pronoun which is used when it is preceded by a preposition. NO COMMAS are used to set off the clause. The pronoun that is more commonly used. |
A nonidentifying (non-restrictive) relative clause adds extra information about a noun already identified by other means, for example, by name, by shared knowledge or context. The clause is just adding interesting information. That is not used in a nonidentifying clause. COMMAS are used before and after the clause. Also see parentheses or dashes. |
The water that I drank last night contained sodium. (identifies the specific one) |
The Evian water, which I drank last night, contained sodium. (adds extra info) |
The car that runs off of a lithium-ion battery is surprisingly fast. |
The Tesla, which runs off of a lithium-ion battery, is surprisingly fast. |
The problem about which I wrote is the subject of today's lecture. |
The Lost Generation , about which I wrote, is the subject of today's lecture. |
The prison that is located in San Francisco Bay was a depressing place to work. |
Alcatraz Prison, which is located in San Francisco Bay, was a depressing place to work. |
lithium-ion battery (n.) – a type of battery used in laptops
depressing (adj.) – causing to feel sad
prison (n) – a building where people are kept as punishment for a crime
Exception — Preposition + Which
| AN IDENTIFYING CLAUSE — IN/ ON/ AT WHICH | A NONIDENTIFYING CLAUSE — WHICH |
|---|---|
Which can be used in an identifying (restrictive) clause when preceded by a preposition: in which, on which, which. |
Otherwise, which is used in a clause not to identify but to add some extra information. |
The day on which it happened was Thursday. |
The day, which you wrote down, was Thursday. |
The situation in which we find ourselves is a difficult one. |
The situation, which we find ourselves, is a difficult one. |
The address at which they live is unlisted in the telephone book. |
The address, which they gave us, is unlisted in the telephone book.
|
Restrictive Clauses
Identifying Words, Phrases and Clauses
Identifying (Restricted) vs. Non-Identifying (Nonrestrictive)
| IDENTIFYING MODIFIER | NON-IDENTIFYING MODIFIER |
|---|---|
NO COMMA is used when adding an identifying clause, which adds information necessary for the identification of a subject or object noun. |
COMMAS are used before and after a clause that adds extra information to a subject or object noun that is already clearly identified. |
NO MODIFIER The store sells organic produce. Which store? |
NO MODIFIER Whole Foods sells organic produce. |
AN IDENTIFYING CLAUSE The store where I shop sells organic produce. |
A NONIDENTIFYING MODIFYING CLAUSE Whole Foods, where I shop, sells organic produce. |
AN IDENTIFYING PREPOSITIONAL PHRASE The store on University Avenue sells organic produce. We went to Whole Foods on University Avenue. |
A NONIDENTIFYING PREPOSITIONAL PHRASE Whole Foods, on University Avenue, sells organic produce. We went to the Berkeley Whole Foods, on University Avenue. |
AN IDENTIFYING PROPER NOUN The store called Whole Foods sells organic
produce. |
A NONIDENTIFYING MODIFYING CLAUSE Whole Foods, a grocery store, sells organic
produce. |
INDENTIFIED BY LATER MENTION IN THE SENTENCE The store that sells organic produce is Whole Foods. |
– |
INDENTIFIED BY EARLIER MENTION IN THE SENTENCE I like Whole Foods; the store sells organic produce. |
– |
A RESTRICTIVE CLAUSE – to a particular area The Whole Foods stores in San Francisco sell Napa Valley cheese. |
A NONRESTRICTIVE CLAUSE Whole Foods, where shoppers can recycle bags, sells organic produce. |
IDENTIFIED BY NAME AND UNIQUENESS The Golden Gate Bridge is actually orange-red. |
A NONIDENTIFYING MODIFYING CLAUSE The Golden Gate Bridge,
which is actually orange-red, is surrounded by fog. |
NOTE: "where I shop" = "in which I shop" = "which I shop in" (informal)
Common Mistakes
| ERROR | FIX |
|---|---|
*The London Bridge which it was in England is now in Arizona.
|
The London Bridge, which was in England, is now in Arizona. |
*The marine iguana that eats algae in the sea is only found in the Galapagos Islands. |
The marine iguana, which eats algae in the sea, is only found in the Galapagos Islands. algae (n.) – a simple plant without stems or leaves that grows in or near ocean water There marine iguana (in the Galapagos) is unique. The modifying clause adds extra information. Add commas. |
*Alcatraz Island surrounded by fog was a depressing place to serve time in prison.
|
Alcatraz Island, surrounded by fog, was a depressing place to serve time in prison. The island is identified by name. The modifying clause adds extra information. Add commas. |
Pop-Q "*Yellow highlighted words are examples of incorrect usage.
Practice
The San Francisco Bay Area
Join the two sentences into one. Decide whether to use commas with the clause:
- Select commas or no commas.
- Read the feedback about your option.