Grammatical number refers to the distinction between singular and plural forms of nouns, pronouns, and verbs. There are several synonyms for the term grammatical number, such as numerical agreement, number agreement, and number marking. These terms all refer to the grammatical system used to indicate whether a word refers to one or more than one object. Some languages have additional number forms, such as the dual form used to indicate two objects, or the trial form used to indicate three objects. Understanding grammatical number is essential for proper communication in any language, as it affects the agreement of other parts of speech in a sentence.