Just thought I'd return to this thread.
I'm not learning Arabic at the moment (my laptop has broken down, I'm basically too poor to get it mended and also buy the kind of learning materials I'd like) but I did see an interesting book in the library. It has a section on the Arabic numbers and counting that explains things for me. The situation is a bit more complicated than counting in English.
In English, it's all very simple: we say one + the singular of the noun, e.g. one cat. Then from two upwards, we say the number then the plural, e.g. two cats, ten cats, twenty men, etc.
There are a few little odd things for the learner of English to be aware of - we sometimes say fifty pound, instead of fifty pounds. And when I talk about my height, I don't say five feet ten inches, I say five foot ten.
Lastly, there are a few informal or regional terms as well - a grand means 1000, K also means thousand, a score means twenty, etc. But it's basically plain-sailing.
And now for numerals and counting in Arabic.
For abstract counting (i.e. counting without the object), Arabic has the following:
1. waahed
2. ithnaaan
3. thalaatha
4. arba3a
5. khamsa
6. sitta
7. sab3a
8. thamaania
9. tis3a
10. 3ashara
I always wondered why 3 to 10 end in -a (in Arabic script, the ending is actually ta marboota, a t that is usually silent) but 1 and 2 don't. The book explains that for abstract counting, 1 and 2 are in the masculine form and 3 to 10 are in their feminine forms.
I want to show you how complicated the number system gets in Arabic, so I'll be comparing two nouns, and how to count with them: bayt ('house', masculine) and bint ('girl', feminine).
To say 'one girl' or 'one house', you don't bother with waahed (1), plus Arabic has no indefinite article (a, an) so you can just say bint or bayt.
To say two houses/girls, again you don't bother with ithnaan (2) because Arabic has a dual ending (-aan) for nouns. So bintaan ... baytaan.
From 3 to 10, you use the numbers with the plural form of the noun. The plural of bayt is buyoot and the plural of bint is banaat. But - and this is where things start getting batsh*t - you have what is known as 'opposite agreement'. This means that if the noun being counted is masculine, you have to use the feminine forms of the numbers, and vice versa for feminine nouns. So ...
thalaath banaat ... thalaathat buyoot
arb3 banaat ... arba3at buyoot
khams banaat ... khamsat buyoot
sitt banaat ... sittat buyoot
sab3 banaat ... sab3at buyoot
thamaani banaat ... thamaaniat buyoot
tis3 banaat ... tis3at buyoot
3ashar banaat ... 3asharat buyoot. (the silent ta marboota is pronounced here when counting masculine nouns.)
From 11 upwards, you use the numeral plus the singular of the noun.
So, 6 houses is sittat buyoot but 60 houses is sitteen bayt. And, from what I remember, when you ask 'How many ... ?' you also have the noun in the singular: kam bint? - how many girls?
There is also the question of case endings, used in the 'highest' form of Arabic, e.g. political speeches, scientific conferences, whatever.
I'll give you one example, one I remember: when asking how many plus masculine noun, you use the singular (as mention directly above) but you also have to add the accusative case ending (-an) onto the noun.
E.g. - kam kalban? - how many dogs?
Kam rajulan? - how many men?
But I'll generally leave case endings out, there's enough craziness in this post already! XD