which

"Which" is a small word with an important job. It helps us choose one thing from a group or ask about a limited set of options. "Which flavor of ice cream do you want?" asks someone to pick from the flavors available. It is also used to add extra information about something already mentioned: "The book, which I borrowed yesterday, was fascinating." In this kind of sentence, it gives added detail without changing the main point. It can also come before a noun, as in "which day" or "which book," to point to one particular thing from several.

The word "which" is used when we are talking about one thing from a known group, set, or range of options. It often appears in questions, in descriptions that add extra information, and before nouns when we want to point to something specific.

In questions, "which" asks someone to choose from a limited set. "Which movie should we watch?" suggests that there are several movies to choose from. In this use, it is different from "what," which can sound more open and less limited. "Which" is useful when the possible answers are already known or understood.

"Which" is also used to introduce extra information about something already mentioned. In "The car, which was red, sped down the street," the part "which was red" adds detail about the car. This extra part is usually set off by commas because it is not the main point of the sentence. In standard usage, "which" commonly introduces this kind of non-essential clause.

It can also work before a noun as a determiner. In phrases like "which day," "which book," or "which road," it points to one specific thing from several possibilities.

Overall, "which" helps speakers and writers make choices clear, identify one item from a group, and add extra detail in a smooth way. It is a small but very useful word in everyday English.