ABSTRACT
An adjective is a word or a group of words used to describe a noun. Adverbs usually modify the verb, an adjective, another adverb, different parts of a sentence or a whole clause; there are many categories of adverbs. An English agent participle usually uses the suffix -er as in singer, driver, advisor; in Persian usually the suffix -ande is used. Attributive adjective is an adjective standing together with the noun that it modifies, in the same part of the sentence. A verb is called auxiliary when it is used not independently as the main verb but as an auxiliary verb helping the main verb to form a certain aspect, mood, and so on, like when 'to have' is used in English to form the perfect aspect of other verbs. Conjunction is a word used to join other words, phrases, clauses or sentences. The three kinds of conjunctions are: correlative, coordinating and subordinating.
