What part of speech is once?

"Once" can be several parts of speech depending on its context:

* Adverb: When it modifies a verb, adjective, or another adverb.

* Example: "I once lived in New York." (modifies the verb "lived")

* Adjective: When it means "one" or "single."

* Example: "We only have once chance." (modifies the noun "chance")

* Conjunction: When it connects two clauses, usually to indicate a specific point in time in the past.

* Example: "Once we reach the summit, we can relax."

To determine the part of speech, look at the context and how the word is used in the sentence.