What part of speech is the word before?

The word "before" can be several parts of speech depending on how it's used in a sentence:

* Preposition: This is the most common use of "before." It shows a relationship of time or place, like "I arrived before you."

* Adverb: "Before" can modify a verb, adjective, or another adverb, indicating time or order. Example: "He finished the race before anyone else."

* Conjunction: "Before" can connect two clauses, showing a time relationship. Example: "We had dinner before we went to the concert."

To determine the part of speech, you need to look at how it's used in the specific sentence.