A Mo’rab word is that word which changes the shape of its ending (last letter) because of its position in the sentence or because of the function it does in the sentence (Grammatical Case). These words are pronounced differently; they have different diacritics (tashkeel تشكيل ) on the last letter.
EX. 1 – Peace is the hope of the world. السلامُ أملُ العالمِ
2 – Peace is the hope of the world. إنَّ السلامَ أملُ العالمِ