What part of speech is the word through?

The word "through" can be several parts of speech depending on how it's used in a sentence. Here are the most common:

* Preposition: This is the most common use. It shows a relationship between a noun or pronoun and another word in the sentence.

* Example: "The cat walked through the door."

* Adverb: This use describes a verb, adjective, or another adverb, usually indicating movement or completion.

* Example: "He read the book through in one day."

* Adjective: This is less common but can be used in some expressions.

* Example: "They had a through examination."

To determine the part of speech, you need to look at how the word is used in the specific sentence.