Genitive Case (الجَرّ)

Arabic uses case endings to show a noun's job. In the genitive case, the noun's job is to follow something. Usually, it follows a preposition or another noun. Imagine a train. The first car is the leader. The second car is the one in the genitive case. The most common sign is the kasra ( ِ ). For singular words, it sits right under the last letter. It is subtle but very important. If the word has Al- (the), it gets one kasra. If it is indefinite (like "a book"), it gets tanween kasr ( ٍ ). Yes, even native speakers forget these in casual speech! But in formal writing or news, it is everywhere. It makes you sound educated and precise. Think of it like a grammar traffic light. It tells the listener, "Hey, this word is attached to the one before it."

1. 1For singular nouns, add a kasra to the last letter. Example: Al-bayti (the house).
2. 2For indefinite singular nouns, add two kasras. Example: Baytin (a house).
3. 3For Sound Masculine Plurals, change the ending from uuna to eena. Example: Mudarrisuuna becomes Mudarriseena (teachers).
4. 4For Dual nouns (two of something), change aani to ayni. Example: Kitaabaani becomes Kitaabayni (two books).
5. 5For Sound Feminine Plurals, use a kasra. Example: Mudarrisaatin (female teachers).
6. 6Note: Some special words (diptotes) are rebels. They might use a fatha instead. Don't worry about those yet. Focus on the kasra and the ya (ي) for now. That is 90% of the work.

Scenario 1: After Prepositions. This is the most common use. If you see fi (in), min (from), ila (to), or bi (with), the next word must be genitive. If you are ordering food and say bi al-lahmi (with meat), you are using Al-Jarr.

Scenario 2: Possession (The Idafa). This is the "X of Y" structure. Think of "The Office of the Boss." In Arabic, we say Maktabu al-mudeeri. The second word (al-mudeeri) must be in the genitive case. It is like a secret handshake between two nouns.

Scenario 3: Adverbs of Place/Time. Words like fawqa (above) or tahta (under) act like prepositions. The word after them takes a kasra. If your keys are tahta al-tawilati (under the table), al-tawilati is genitive. Use this when giving directions to a taxi driver.

Do not use Al-Jarr for the subject of a sentence. The person doing the action usually takes the damma (nominative). If you say "The teacher (subject) went to the school," only "school" is genitive. Do not use it for the direct object either. If you "eat the apple," the apple is usually in the accusative (fatha). Also, the first word in a possession pair (the Idafa) is never genitive just because it's first. It depends on its own job in the sentence. Only the second word is locked into the genitive case. Think of the first word as a flexible leader and the second as a loyal follower.

One big mistake is putting Al- on the first word of an Idafa. People say Al-kitabu al-talibi. Incorrect! It should be Kitabu al-talibi (The student's book). The first word loses its Al- but remains specific. Another mistake is forgetting the plural change. Many learners say ma'a al-mudarrisuuna. Ouch! It should be ma'a al-mudarriseena. Think of it like wearing mismatched shoes. People will understand you, but it looks a bit funny. Also, don't over-kasra! Only use it when there is a clear reason. If there is no preposition or possession, leave the kasra alone. Even the most confident students trip over this at least once.

How is this different from adjectives? In an adjective phrase like "The big house" (Al-baytu al-kabeeru), both words match. If the first is damma, the second is damma. But in an Idafa (possession), the second word is ALWAYS genitive. It doesn't care what the first word is doing. It is independent and stubborn. Also, don't confuse Al-Jarr with the ya used for "my." If you say Kitabi (my book), that ya is a pronoun, not just a case ending. However, because it's attached to a noun, it technically puts that noun in a genitive state too! It’s all connected in the end.