Rule 1: 1. كَمْ with the accusative singular
كَمْ how many? how much? is followed by the thing counted in the accusative singular with tanwīn, even when the answer will be plural: كَمْ أَرْنَبًا؟ how many hares?, literally how many, as to hare? The sentence then continues normally. The answer uses the ordinary forms: أَرْنَبَيْنِ two hares, أَرَانِبَ كَثِيرَةً many hares.
كَمْ أَرْنَبًا صِدْتَ أَمْسِ؟
kam arnaban ṣidta amsi
How many hares did you hunt yesterday?
كَمْ مَرَّةً زُرْتَ الْغَابَةَ؟
kam marratan zurta-l-ghābata
How many times did you visit the forest?
مَرَّةً, the accusative you learnt in lesson 49.
كَمْ وَلَدًا لَكَ؟ لِي وَلَدَانِ.
kam waladan laka? lī waladāni
How many children do you have? I have two children.
The question has a singular, the answer a dual.
كَمْ كَلْبًا عِنْدَ الصَّيَّادِ؟
kam kalban ʿinda-ṣ-ṣayyādi
How many dogs does the hunter have?