* Noun: When referring to the state of matter, like "Water is a liquid."
* Adjective: When describing something that is in liquid form, like "The liquid in the bottle is clear."
* Verb: While not common, it can be used as a verb to mean "to make liquid," like "Heat the butter to liquid."
Let me know if you have a specific sentence in mind, and I can help you figure out the part of speech for "liquid" in that context!