How to say "two" in Arabic
CognateMeaningtwo
Arabic · Modern Standard Arabic
ithnānאת'נאן
اثنان
Hebrew · Modern Hebrew
shnayimشْنَايِم
How the two words are related
Same Semitic root, same meaning — you already know this word.
Arabic root
ث-ن-يHebrew root
ש-נ-יHebrew ש regularly answers to Arabic ث, so שניים and ithnān are the same Proto-Semitic 'two' in different clothes. The Hebrew dual ending ־ַיִם and the Arabic ـَان are parallel tricks, too.
Learn it
On the street
How people actually say it in the spoken dialects, where it differs from the standard word.
Levantine · Palestine, Jordan, Lebanon, Syria
MSA ث becomes t in the dialect and the word gets clipped: tnēn.
Egyptian · Cairo and the Nile Delta
Cairo adds a helping vowel: itnēn.
Moroccan · Morocco — Casablanca, Rabat, Fes
Darija's two is a different word altogether: jūj, from zawj, 'a pair'.
In a phrase
two and two is four