Lesson 15 of 16 · The patterns behind the words
What the endings are telling you
الْإِعْرَاب
After this lesson: Read -u, -a and -i at the end of a noun as information about its job.
The short vowel at the end of an Arabic noun is not decoration. It reports the noun's job in the sentence, and it is the reason Arabic can move words around without losing the meaning.
Marfūʿ, ending in -u, marks the subject of a nominal sentence and the doer of a verb. Manṣūb, ending in -a, marks the object of a verb, and the subject after inna. Majrūr, ending in -i, marks a noun after a preposition and the second noun of an 'of' phrase.
Read al-Fātiḥah 1:2 with this in mind and it explains itself: al-ḥamdu ends in -u because it is the subject; li-llāhi ends in -i because a preposition precedes it; rabbi ends in -i because it describes llāhi, which is majrūr; al-ʿālamīn is the second term of an 'of' phrase.
In the Qur'an
ٱلْحَمْدُ لِلَّهِ رَبِّ ٱلْعَـٰلَمِينَ
al-ḥamdu li-llāhi rabbi l-ʿālamīn
All praise belongs to Allah, Lord of all the worlds.
Notice. Every ending in this āyah is explained by a rule you have already learned.
تَبَارَكَ ٱلَّذِى بِيَدِهِ ٱلْمُلْكُ
tabāraka lladhī bi-yadihi l-mulk
Blessed is He in whose hand is the dominion.
Notice. Al-mulku ends in -u: it is the subject, even though it arrives after the phrase about it.
Watch out. Dual and sound plural nouns show their case with letters rather than vowels: -ūna against -īna, -āni against -ayni. Same information, different signal.
Check yourself
Nothing is scored or saved here — answering is how the rule sticks. When you want a score, the same checks are drilled to mastery below.
A noun ends in -i. Which is most likely?
Why can Arabic move words out of their usual order?
Word morphology, grammar and syntax trees are shown by the Quranic Arabic Corpus (corpus.quran.com), the annotated linguistic resource developed at the University of Leeds.