In this English vocabulary lesson, learn how to use "honest, honesty, honestly". All three of these words are about being truthful, trustworthy or telling the truth. The difference is simply how they're used in a sentence because of their function. Honest is an adjective. It's most commonly used with the very to be. It can also be used without the verb to be to describe a noun. Honesty is a noun. It's used to talk about the concept of being honest. Honestly is an adverb. It's used to describe a