Restrictive phrases are essential to the meaning of a sentence and specifically identify the noun they modify. Here's how you should handle them:
- Restrictive phrases should not be enclosed in commas. This is because they are necessary for understanding which specific person or thing the sentence refers to.
For example:
- The students who study hard will pass the exam. (Here, "who study hard" is a restrictive phrase identifying which students.)
In contrast, non-restrictive phrases provide additional information but are not essential to the sentence's meaning and should be enclosed in commas.
For example:
- The students, who study hard, will pass the exam. (Here, "who study hard" adds extra information but isn't necessary to identify the students.)
So, to summarize: restrictive phrases should not be enclosed in commas.