How to say "why" in Arabic
CognateMeaningwhy
Arabic · Modern Standard Arabic
لِمَاذَا
limādhāלמאד'א
لماذا
Hebrew · Modern Hebrew
למה
lamaلَامَا
How the two words are related
Cognate
Same Semitic root, same meaning — you already know this word.
Built from the same bones as Hebrew לָמָּה: the preposition لـ/לְ ('for, to') plus the ancient interrogative ما/מָה ('what') — Arabic just tacks on an extra demonstrative ذا ('that') that Hebrew dropped. Strip the ذا and limādhā is, letter for letter, למה.
Learn it
On the street
How people actually say it in the spoken dialects, where it differs from the standard word.
Egyptian · Cairo and the Nile Delta
لِيه
lēhליהCairo's why is lēh, at the end of the sentence: ʿamalt kida lēh?
Moroccan · Morocco — Casablanca, Rabat, Fes
عْلَاش
ʿlāshעלאשDarija's why is ʿlāsh.
In a phrase
لِمَاذَا تَضْحَك؟
limādhā taḍḥakלמאד'א תצ'חךWhy are you laughing?