I. Adjectives
An Adjective is a word that modifies a noun or a pronoun by describing, identifying, or quantifying it. An adjective usually comes before the noun it modifies or after a linking verb. Sometimes, it comes after the object of such verbs as find, make, keep, etc.
 A successful project
 (Modifying the noun project)
 The project is successful:
 (Functioning as a subject complement)
 I found it easy.
 (Functioning as an object complement)

II. Adverbs

An Adverb is a word that describes a state or an action in more detail by indicating manner, time, place, cause, or degree... An adverb can modify a verb, an adjective, another adverb, or a whole sentence. It is formed by adding the suffix -ly to an adjective (e.g. careful -carefully, safe - safely, skillful - skillfully). Examples:
 I completely forgot about the meeting.
 (Modifying the verb forgot)
 That was very- useful.
 (Modifying the adjective useful)
 Thank you very much.
 (Modifying the adverb much)
 Unfortunately, / couldn't make it.
 (Modifying the whole sentence)

Note: Not all words ending in -ly are adverbs. There are some adjectives that are formed by adding -ly to their nouns. friend - friendly love - lovely