Dual

Dual. In nouns, pronouns, and verbs in some of the Aryan and Semitic languages, besides the inflexions of the singular and plural, there is a third set, expressing the existence or action of two persons or things. This "dual number" is probably older than the plural, and usually is tending to disappear. In Sanscrit and ancient Greek it tends to disappear. In some dialects of the latter it is not found at all, and it had vanished altogether by the time of Alexander the Great. In Latin there is only one trace of it (in ambo, both), and it is not found in the Germanic languages.