Adjective is an important part of speech and must in learning grammar.Without proper usage of adjectives your written and spoken English will never improve. Since it adds something to the meaning of the noun or the verb so while writing and speaking you often use verbs and nouns. Therefore your sentence can never be complete without using adjective properly.
In addition to the adjective you need to know a lot about other parts of speech so you can use a very good resource of learning grammar here
In addition to the adjective you need to know a lot about other parts of speech so you can use a very good resource of learning grammar here