In short

English owns things with a separate little word in front: “my book”, “her car”. Arabic owns them with an ending glued to the back of the noun: كِتابي، سَيّارَتُها. There is no space, no apostrophe and no extra word - the pronoun becomes part of the noun, and the noun grows a syllable or two. The previous lesson gave you the free-standing pronouns أَنا، أَنْتَ، هُوَ; this lesson gives you their attached twins, which are the forms you will actually write most of the time.

Two consequences follow immediately, and they are what makes this lesson worth reading twice. First, a noun carrying one of these endings is already definite - “my book” is a particular book - so it refuses الـ and it refuses tanwīn. Second, the very same endings attach to prepositions: لَهُ، مِنْهُ، عَلَيْها، مَعَنا. Learn the set once and you have covered nouns and prepositions together, with only small, predictable adjustments at the seam.

The rule

1. Twelve endings, one set. Arabic has an attached pronoun for every person that the independent pronouns cover: ـي، ـكَ، ـكِ، ـهُ، ـها، ـنا، ـكُما، ـكُمْ، ـكُنَّ، ـهُما، ـهُمْ، ـهُنَّ. They are written joined to the host word, never separated by a space, and the host keeps its own vowelling in front of them: كِتابُكَ is one word of four syllables. Notice the internal logic - ك means “you” throughout, ه means “he / she / they”, ن means “us”, ي means “me”. Everything after that first consonant is just the number-and-gender tail you already met on the independent pronouns.

2. ـي swallows the case ending. Eleven of the twelve endings sit on top of the noun’s normal final vowel: كِتابُ + كَ = كِتابُكَ, with the ḍamma still audible. The first-person ـي is different. It takes the last consonant of the noun for itself, and the case ending disappears underneath it:

• كِتابٌ / الكِتابُ → كِتابي - never *كِتابُي، never *كِتابٌي
• بَيْتٌ → بَيْتي، صَديقٌ → صَديقي، اِسْمٌ → اِسْمي

The result is invariable. Whatever the sentence does with the word, “my book” stays كِتابي: كِتابي جَديدٌ (subject), قَرَأْتُ كِتابي (object), فِي كِتابي (after a preposition). That is one form to learn instead of three, so the most useful ending in the language is also the easiest.

3. A suffixed noun is definite - no الـ, no tanwīn. This is the rule beginners break most often. The ending points at a specific owner, which makes the noun specific, so the two ordinary markers of definiteness and indefiniteness are both blocked:

• الكِتابي is impossible - the article and the suffix cannot share a word
• كِتابٌي and كِتابًكَ are impossible - tanwīn cannot survive a suffix

An adjective describing such a noun must agree in definiteness, and since the noun is definite the adjective takes الـ: كِتابي الجَديدُ “my new book”, سَيّارَتُها الحَمْراءُ “her red car”. Drop that article and you have changed a phrase into a sentence: كِتابي جَديدٌ means “my book is new”. Both are correct Arabic; only one of them is what you meant. (Definiteness itself is lesson 4; adjectives are lesson 8.)

If you really do want an indefinite “a book of mine”, Arabic does not use a suffix on the noun at all - it says كِتابٌ لي, keeping the tanwīn and putting the pronoun on a preposition instead.

4. ة becomes ت. The tied tāʾ marbūṭa exists only at the very end of a word. The moment anything is added behind it, it unties into an ordinary ت and takes the case vowel normally:

• سَيّارَةٌ → سَيّارَتي، سَيّارَتُكَ، سَيّارَتُها
• مُعَلِّمَةٌ → مُعَلِّمَتُهُ، غُرْفَةٌ → غُرْفَتُنا، مَدْرَسَةٌ → مَدْرَسَتُهُمْ

Write *سَيّارَةي and you have written a letter that cannot occur in that position. This same untying will come back in the إِضافَة (lesson 20), so it is worth fixing now.

5. The host keeps its own case. The suffix does not freeze the noun. Whatever ending the sentence calls for is still there, sitting between the noun and the suffix:

• كِتابُهُ جَديدٌ - subject, so مَرْفوع
• قَرَأْتُ كِتابَهُ - object, so مَنْصوب
• فِي كِتابِهِ - after a preposition, so مَجْرور

Three different words, one meaning. In unvocalized writing all three are spelled كتابه, so only the context tells you which one is meant. Speech is kinder here than the page: the suffix shelters the case vowel, so even when you stop at the end of a sentence and drop the last vowel - كِتابُهْ، كِتابَهْ، كِتابِهْ - the three stay apart, even in the pausal form. So this distinction is real grammar that the writing hides - which is exactly why this path prints every vowel.

6. هُ harmonizes to هِ. The third-person endings that begin with ه change their vowel when what comes immediately before them is a kasra, a long ī, or the diphthong ay. The ḍamma flips to a kasra to match:

• بِ + هُ = بِهِ، في + هُ = فيهِ، عَلى + هُ = عَلَيْهِ
• كِتابِ + هُ = كِتابِهِ، فِي بَيْتِهِمْ، مِنْ مُعَلِّمَتِهِنَّ

All four ه-forms behave this way: هُ → هِ، هُما → هِما، هُمْ → هِمْ، هُنَّ → هِنَّ. After a fatḥa, a ḍamma, a long ā or a sukūn, they keep the ḍamma: كِتابُهُ، كِتابَهُ، مِنْهُمْ، عِنْدَهُنَّ. This is pure sound harmony - the tongue stays where it already is - and once you notice it you will stop having to think about it.

7. The same endings on prepositions. Prepositions take the identical set - and so do مَعَ and عِنْدَ, which are strictly ظُروف rather than حُروف جَرّ (lesson 16) but carry the endings in exactly the same way. Preposition plus pronoun is written as one word:

• لِ (to, for): لي، لَكَ، لَهُ، لَها، لَنا، لَكُمْ، لَهُمْ
• بِ (with, by): بي، بِكَ، بِهِ، بِها، بِنا، بِكُمْ، بِهِمْ
• مَعَ (with): مَعي، مَعَكَ، مَعَهُ، مَعَنا، مَعَكُمْ
• عِنْدَ (at, by): عِنْدي، عِنْدَكَ، عِنْدَهُ، عِنْدَنا

Four seams need attention, and they are all small:

• مِنْ and عَنْ double their ن before ـي and ـنا: مِنّي، مِنّا، عَنّي، عَنّا. With every other ending they are unchanged: مِنْكَ، مِنْهُ، عَنْها، عَنْكُمْ.
• لِ switches its kasra to a fatḥa in front of every ending except ـي: لَكَ، لَهُ، لَنا، لَهُنَّ - but لي, where the lām keeps its original kasra.
• عَلى and إِلى turn their final ى back into a ي: عَلَيْكَ، عَلَيْها، إِلَيْنا، إِلَيْهِمْ. With the first person the two yāʾs fuse into one doubled letter: عَلَيَّ، إِلَيَّ.
• في does the same in the first person only: فِيَّ, against plain فيكَ، فيهِ، فينا.

8. What this lesson is not. Three neighbouring topics use the same endings or the same idea, and each has its own lesson. Attaching a pronoun to a verb to say “he saw me, I asked him” is lesson 29 - the set is nearly identical, with one difference worth waiting for. Owning something by putting two nouns together - بابُ الْبَيْتِ, “the door of the house” - is the إِضافَة, lesson 20. And saying “I have a car” with عِنْدي or لي is lesson 17. Here we stay with the plain suffix on a noun or a preposition.

9. Flags for later. A dual host and a sound masculine plural host both drop their final ن before a suffix (كِتابانِ → كِتاباهُ، مُعَلِّمونَ → مُعَلِّموهُ); meet the forms in lessons 9 and 12 and the mechanism in lesson 40. A small group of very common nouns - أَبٌ، أَخٌ and their like - stretch the case vowel into a long letter before a suffix: أَبوهُ، أَخوهُ، أَباهُ، أَبيهِ. The one you need today is the harmless first person: أَبي “my father”, أَخي “my brother”.

Forms & patterns

The full set on a masculine noun in the nominative. The dual rows are printed for completeness - recognize them, but expect to use the other ten far more often.

Nouns ending in ة, across four of the endings. The pattern is the same for all twelve:

The host’s own case ending survives underneath the suffix - and drags the ه-forms with it:

The endings on five common prepositions:

And on the four that reshape themselves at the seam:

The dual slots into both preposition tables exactly where you would expect: لَكُما، لَهُما، مِنْكُما، مِنْهُما، عَلَيْكُما، عَلَيْهِما، فيكُما، فيهِما.

Examples

Common mistakes

• كِتابُي -> كِتابي - the first-person ي takes the last consonant for itself and the case vowel vanishes. There is no ḍamma to write.
• الكِتابي -> كِتابي - a suffix already makes the noun definite, so الـ has nothing left to do. One definiteness marker per word.
• بَيْتٌكَ -> بَيْتُكَ - tanwīn cannot stand in front of a suffix either. The doubled sign becomes a single case vowel.
• سَيّارَةي -> سَيّارَتي - ة exists only word-finally. Add anything behind it and it unties into ت.
• كِتابي جَديدٌ (meaning “my new book”) -> كِتابي الجَديدُ - the noun is definite, so the adjective needs الـ. Without it you have written the full sentence “my book is new”.
• بِهُ / فيهُ / عَلَيْهُ -> بِهِ / فيهِ / عَلَيْهِ - after a kasra, a long ī or ay, the ه-endings take a kasra to match.
• فِي كِتابُهُ -> فِي كِتابِهِ - the preposition still governs the noun underneath the suffix, and that kasra then pulls هُ down to هِ as well.
• مِنْي / عَنْي -> مِنّي / عَنّي - the ن of مِنْ and عَنْ doubles before ـي and ـنا. Same for مِنّا، عَنّا.
• عَلَيْي / إِلَيْي -> عَلَيَّ / إِلَيَّ - the two yāʾs merge into one letter with a shadda, and the fatḥa before them stays.
• لِكَ / لِهُمْ -> لَكَ / لَهُمْ - لِ takes a fatḥa in front of every ending but ـي.
• كِتاب أَنا -> كِتابي - the independent pronouns of lesson 6 never mark possession. That job belongs to the attached set only.

Tips

• Chant one noun straight through all twelve: كِتابي، كِتابُكَ، كِتابُكِ، كِتابُهُ، كِتابُها… Then do it again with سَيّارَة so the ة → ت switch becomes automatic rather than remembered.
• Hook the consonants, not the whole endings: ك = “you”, ه = “he / she / they”, ن = “we”, ي = “me”. The rest of each ending is the same tail you learned on the independent pronouns.
• Two of the twelve are duals. Learn to recognize ـكُما and ـهُما in reading; you can leave producing them until lesson 12.
• Before you write الـ on any noun, check whether it already ends in a suffix. If it does, stop - the word is finished.
• Read كِتابُهُ، كِتابَهُ، كِتابِهِ aloud as a set. The vowel harmony of هُ / هِ is easier to hear than to memorize.
• Ordinary Arabic prints كتابه with no vowels at all, so context - not the spelling - tells you the case. Do not let that worry you; that is what the pronunciation guide’s lesson on reading unvocalized text is for.
• Ignore for now what happens when the host is a dual or a sound masculine plural, and ignore the pronoun-on-a-verb set entirely. Both arrive later with their own lessons.
• The prepositions are worth over-learning early: لي، لَهُ، مَعَهُ، عِنْدَها، مِنْهُمْ، عَلَيْكُمْ turn up in every conversation, and they never change afterwards.