Noun is any name used to label something. Pronoun is used to substitute the nouns to avoid repeated names. Adverb is a word that describes verbs, adjectives, or another adverb. Adjective describes noun and pronoun. Verb tells an action. Homonym are two words which has similar pronunciation. Synonym are two words that have same meaning. Prefix is an affix placed before the root word. Suffix is an affix placed after the root word. The verb "be" can be replaced by is, are, was, were, etc.