Dual nouns (ـان / ـين)

The Dual Number

Arabic has a specific grammatical number for exactly two of something, called the dual.

You form the dual by adding a suffix directly to the end of a singular noun. The default dual suffix is ـان.

Since paired body parts (like eyes, ears, and hands) are generally feminine in Arabic, adjectives describing them take the feminine dual suffix, ـتان.

The Dual After Prepositions

The dual suffix changes depending on its grammatical role.

While you use ـان (or ـتان) for the subject of a sentence, the suffix changes to ـين (or ـتين) whenever the noun comes after a preposition (like بـ "with" or على "on") or acts as the direct object of a verb.

Notice how the dual suffix and its matching adjective change in the following sentences: