The Indefinite Ending

Level 1

Tanwin (التنوين) is a double-vowel mark at the end of a word that sounds like an 'n'. It usually acts like the English word 'a' or 'an', indicating that a noun is indefinite.

How It Works

1. The Three Forms of Tanwin
Tanwin is a property exclusive to nouns and adjectives; it is not found on verbs in standard usage. While it often marks a word as indefinite, it is technically a marker of declinability and appears on many definite proper names. It also indicates the word's grammatical case. Adjectives must match the noun in case and definiteness. Note that if a noun is a definite proper name that takes Tanwin (like مُحَمَّدٌ), its adjective will take the definite article and thus lose its Tanwin:

  • ـٌ (Dammatayn): The nominative case (subject). Pronounced '-un'. Example: كِتَابٌ.
  • ـً (Fathatayn): The accusative case (object). Pronounced '-an'. Example: كِتَابًا.
  • ـٍ (Kasratayn): The genitive case (after prepositions). Pronounced '-in'. Example: كِتَابٍ.

2. The Supporting Alif
When using the '-an' ending (Fathatayn), most words require a 'supporting alif' (ا) at the end, such as بَيْتًا. In modern typography, the double fatha is often written on the letter before the Alif (e.g., كِتَابًا), though you may also see it placed directly on the Alif. You do not add this alif if the word ends in Taa Marbuta (ة), a Hamza preceded by Alif (اء), an Alif Maqsura (ى), or a Hamza sitting on an Alif (أ). However, if a Hamza is preceded by a consonant other than Alif, the supporting Alif is still required. If that consonant cannot connect to the left (like 'z' in جُزْء), the Hamza stays on the line (جُزْءًا). If the consonant can connect (like 'y' in شَيْء), the Hamza moves onto a 'seat' called a nabra (شَيْئًا).

3. Mutual Exclusivity
A word can never have both the definite article (Al-) and Tanwin. If you add 'Al-', the double vowel drops to a single short vowel (e.g., كِتَابٌ becomes الكِتَابُ). Similarly, the first word in an Idafa (possession) construction cannot take Tanwin.

4. Pronunciation in Pause (Waqf)
When you stop speaking at the end of a sentence (a pause), the pronunciation changes: the '-un' and '-in' sounds are dropped entirely (becoming a silent sukun), while the '-an' sound changes into a long 'aa' sound (ا). However, if the '-an' ending is on a Taa Marbuta (ةً), it is pronounced as a silent 'h' or 'ah' sound in pause.

5. Proper Names and Exceptions
Many masculine proper names like مُحَمَّدٌ take Tanwin even though they are definite. However, some names are Diptotes, meaning they never take Tanwin. Diptotes use a single Fatha instead of a Kasra in the genitive case (e.g., إلى أَحْمَدَ). This group includes names like أَحْمَدُ and عُمَرُ, and most feminine names. Note: Tanwin is also dropped from a name if it is immediately followed by the word 'ibn' (son of) in a lineage, such as مُحَمَّدُ بن عَبْدِ اللهِ.

Examples (5)

  1. هَذَا كِتَابٌ جَدِيدٌ.

    This is a new book.

    Word by Word: This [is] book [indefinite] new [indefinite].

    Both 'book' and 'new' take the '-un' ending because the noun is indefinite and acts as the predicate (nominative case).

  2. قَرَأْتُ قِصَّةً جَمِيلَةً.

    I read a beautiful story.

    Word by Word: I read story [indefinite] beautiful [indefinite].

    The '-an' ending is used here for the direct object. Note that no extra Alif is added because the words end in Taa Marbuta (ة).

  3. سَكَنْتُ فِي بَيْتٍ كَبِيرٍ.

    I lived in a big house.

    Word by Word: I lived in house [indefinite] big [indefinite].

    The '-in' ending is used because the noun follows a preposition, putting it in the genitive case.

  4. شُكْراً جَزِيلاً.

    Thank you very much.

    Word by Word: Thanks [indefinite] many [indefinite].

    This common expression uses the '-an' ending with a supporting Alif. In speech, this is one of the few times Tanwin is often pronounced even in casual settings.

  5. مُحَمَّدٌ الطَّالِبُ ذَكِيٌّ.

    Muhammad the student is intelligent.

    Word by Word: Muhammad [indefinite] the student intelligent [indefinite].

    Even though 'Muhammad' is a definite proper name, it takes Tanwin. However, its adjective 'the student' must take the definite article 'Al-' to match that definiteness, and thus the adjective loses its Tanwin.

Common Mistakes

  • Writing the 'n' sound as a literal letter Nun (ن).

    كِتَابُن
    كِتَابٌ

    Tanwin is a vowel mark, not a letter. Beginners often mistakenly write the letter Nun because that is how it sounds.

  • Using both the definite article 'Al-' and Tanwin on the same word.

    الكِتَابٌ
    الكِتَابُ

    A word cannot be both definite and indefinite at the same time. Adding 'Al-' forces the Tanwin to become a single short vowel.

  • Forgetting the supporting Alif for the '-an' ending.

    وَلَدً
    وَلَدًا

    Most nouns require an Alif to carry the Fathatayn (ـً) ending unless they end in specific letters like Taa Marbuta.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

The Indefinite EndingLevel 1

Learn This First

To understand Tanween (nunation), you must first be familiar with the basic short vowel marks it doubles. You also need to recognize nouns as the specific word class that takes this ending, and understand the definite article 'Al' because a word cannot have both 'Al' and Tanween at the same time.

Learn Next

Patterns that build on this one.

And 3 more in the full list.