IXL | Commas with nonrestrictive elements

If the relative clause in bold is nonrestrictive, set it off with a comma. If it is restrictive, submit the text without making any changes.

One of the main characters in 2001: A Space Odyssey is a computer that has been programmed to think like a human.

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question

If the relative clause in bold is nonrestrictive, set it off with a comma. If it is restrictive, submit the text without making any changes.

Cindy stared at the last question, but try as she might, she could not remember the name of the man who developed the first polio vaccine.

key idea

Use commas to set off nonrestrictive information in a sentence. Nonrestrictive information is supplemental; it is not necessary in order for a reader to identify who or what is being discussed. Without the information, the meaning of the sentence would still be clear.

The Golden Gate Bridge, which first opened in 1937, took over four years to build.

The underlined information isn't required to interpret the sentence.

The Golden Gate Bridge took over four years to build.

Without the information, a reader still knows which bridge took four years to build.

Do not use commas to set off restrictive information in a sentence. Restrictive information is necessary in order for a reader to identify exactly who or what is being discussed. Without the information, the meaning of the sentence would become unclear.

The author J.K. Rowling was born in Yate, England.

The underlined information helps a reader identify which author is being discussed.

The author was born in Yate, England.

Without the information, a reader doesn't know which author is being discussed.

solution

The relative clause who developed the first polio vaccine is restrictive. The information is needed to narrow down the man being discussed, so do not set off the relative clause with a comma.

Cindy stared at the last question, but try as she might, she could not remember the name of the man who developed the first polio vaccine.

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