Two Types of Arabic Sentences:
1. Verbal sentence (AlJumlatul fi'iliyyatu): the sentence starts with the verb
and subject follows. The verb always in singular form even for the cases
where the subject is dual or plural.
Examples for the verbal sentence:
dhahaba abiy ila Cairo - literal translation - has gone my father to Cairo. But, it really means - my father has gone to Cairo.
raja'a abiy min Cairo - literal translation - returned my father from Cairo. But, it really means - my father returned from Cairo.
la'iba al-waladaani - the two boys played (dual).
la'iba al-awlaadu - the boys played.
As you see, the verb is always in the singular form even though the subject is in dual or plural.
2. Nominal sentence (AlJumlatul ismiyyatu): the sentence starts with the
noun or subject and the others follow. The verb must agree with the subject
in number and gender.
Examples for the nominal sentence:
abiy raja'a min Cairo - My father returned from Cairo.
akhiy kataba - my brother wrote.
al-waladu la'iba - the boy played.
al-waladaani la'ibaa - the two boys played (dual).
al-awlaadu la'iboo - boys played (boys is plural = "they" so the equivalent verb for "they" is "la'iboo").
As you see, the verb agrees with the subject in number.
anaa wa akhiy wa abiy dhahabnaa ila Cairo - I and my brother and my father went to Cairo. In this sentence, I, and my brother and my father are equivalent to "us." Therefore, the verb must agree with the "us," e.g., dhahabnaa.