Case: the property of a noun or pronoun that indicates how it relates to other parts of a sentence. The three cases in English are nominative, possessive, and objective.
Collective noun: a count noun referring to a group—e.g., staff, band, group.
Comparative: indicating that something has a quality to a greater or lesser degree than something else. For example, faster, prettier, and more equitable are comparative adjectives. Comparative adverbs usually take more.
Complement: a word or phrase that completes the meaning of a verb. The main types are objects, predicate nouns, and predicate adjectives.
Conjunction: a word or phrase that links words, phrases, clauses, or sentences.
Conjunctive adverb: an adverb that functions as a conjunction—for example, however, therefore, hence.
Contraction: an abbreviation of a word or phrase formed by omitting letters, usually replacing the omitted letters with an apostrophe—e.g., can’t, we’ll, he’d.
Conventional: significantly more common than alternative forms.
Count noun: a noun that can be singular or plural.