1. We make many adverbs by adding -ly to an adjective, for example:
quick (adjective) > quickly (adverb)
careful (adjective) > carefully (adverb)
beautiful (adjective) > beautifully (adverb)

2. But not all words that end in -ly are adverbs. The following -ly words, for example, are all adjectives:
friendly, lovely, lonely, neighbourly

3. And some adverbs have no particular form. Look at these examples:
example : well, fast, very, never, always, often, still