Plural's a grammatical number, typically referring the more of people to more than one of the referent in the real world. In the English language, singular and plural are the only grammatical numbers. Examples of plural forms: car - cars, boat - boats, house - houses, friend - friends. Other languages In many languages, including a number of Indo-European languages, and Arabic language there's also a dual number (used for indicating two objects). Some other grammatical numbers present in variou… (More on Plural)