The Dual Form and Cases
In Arabic, when you refer to exactly two of something, you use the dual form. Unlike singular nouns, which use short vowels to show their grammatical case, dual nouns show their case by changing their letter suffix.
The Nominative Dual (ـان)
When a dual noun acts as the subject or predicate of a sentence, it is in the Nominative case. You form the Nominative dual by adding the suffix ـان to the end of the singular noun.
| The two stores are open today. | المتجران مفتوحان اليوم.al-matjarâni maftûḥâni al-yawma. |
| The two customers are in the restaurant. | الزبونان في المطعم.az-zabunâni fil-mat'ami. |
Notice in the first sentence that both the subject (المتجران) and its predicate (مفتوحان) take the Nominative ـان ending to match.
The Accusative and Genitive Dual (ـين)
If the dual noun is the direct object of a verb, it is in the Accusative case. For the Accusative, the suffix changes from ـان to ـين.
| Did the man sell the two stores? | هل باع الرجل المتجرين؟hal bâ'a ar-rajulu al-matjarayni? |
Just like in the Nominative case, any adjectives describing the noun must match it. An adjective describing an Accusative dual noun will also take the ـين suffix.
| I bought two new shoes. | اشتريت حذاءين جديدين.ishtaraytu hithâ'ayni jadîdayni |
The exact same ـين suffix is used for the Genitive case, which is required when a noun immediately follows a preposition.
| We found the money in the two coats. | وجدنا المال في المعطفين.wajadnâ al-mâla fî al-mi'ṭafayn |
Contrasting the Cases
When using dual nouns, always identify whether the noun is doing the action (Nominative) or receiving the action (Accusative). Compare these two sentences to see how the noun changes based entirely on its grammatical role:
| You have two different options. | عندك خياران مختلفان.'indaka khiyârâni mukhtalifân |
| I did not understand the two options. | ما فهمت الخيارين.mâ fahimtu al-khiyârayn |
