which

The word "which" is a pronoun used to introduce a clause or to specify a particular thing among a set of items. It's commonly used to ask questions or to provide additional information about something mentioned previously.

Examples:

• Question: "Which book do you prefer?"
• Statement: "The book, which I read last week, was fantastic."

Key Differences with Synonyms:

1. What:

   • "What" is used to ask for information in a broader sense. For example, "What do you want?" is more general than "Which do you want?" which implies selection from specific options.

2. That:

   • "That" can sometimes be used interchangeably with "which," but "that" is generally used for defining clauses, while "which" is seen in non-defining clauses (providing additional information). For example: "The car that is red is mine" vs. "My car, which is red, is parked outside."

Overall, "which" helps to clarify and specify items within a given context, distinguishing it from more general terms.