Brian is giving Sara suggestions for finding a roommate. He says, “If she answers honestly, you’ll know if living together is going to work.” He uses an adverb.
Adverbs are words that modify or describe other words. They can modify verbs, as in, “He speaks softly.” Or they can modify adjectives, as in, “This room is quite large.” Or they can even modify other adverbs, as in, “He walked very slowly.”
You can turn many adjectives into adverbs by adding -ly to the end, as in quietly, quickly, slowly, or gladly. In his quotation, Brian uses the adverb honestly. To make this adverb, he adds –ly to the adjective honest. But be careful! This pattern isn’t true 100% of the time. For example, this doesn’t work for adjectives that already end in -y, such as happy. The adverbial form of happy is happily.