* Noun: "The taste of the chocolate was exquisite." (refers to the sensation itself)
* Verb: "I taste something burning in the kitchen." (refers to the act of using your taste buds)
* Adjective: "This wine has a taste that is both sweet and tart." (describes a quality or characteristic)
Let me know if you have a specific sentence in mind, and I can tell you for sure which part of speech it is in that instance.