what is it?
Turkish has two sets of numbers. Cardinal numbers (bir, iki, üç …) express quantity — how many of something there are. Ordinal numbers (birinci, ikinci, üçüncü …) express rank or position — which one in a sequence. Ordinals are formed by attaching the suffix -(I)ncI to the cardinal. The special word ilk (first) is an alternative to birinci and is very common in everyday use.
when to use it
Counting and quantity: use a cardinal number directly before the noun. The noun stays singular — Turkish does not pluralise a noun when a numeral already shows quantity.
Compound numbers: place the parts in descending order (hundreds → tens → units) with no connector word between them.
Rank, position, or sequence: use an ordinal number. Ordinals behave like adjectives and precede the noun they modify.
"First" with ilk: ilk and birinci are interchangeable in most A1 contexts. ilk is uninflected and is often preferred before nouns.
formation
Compound cardinals are built by juxtaposition with no linking word: yüz yirmi üç = 123.
To form an ordinal, attach -(I)ncI to the cardinal. The suffix has four vowel-harmony variants — -inci, -ıncı, -üncü, -uncu — chosen to match the last vowel of the stem. Two additional rules apply:
Vowel-final stems: the initial I of the suffix drops to avoid a double vowel. iki → ikinci (not *ikiinci).
Final t → d softening: dört → dördüncü (the final t voices to d before the vowel-initial suffix).
| cardinal | ordinal | meaning |
|---|---|---|
| bir | birinci | first |
| iki | ikinci | second |
| üç | üçüncü | third |
| dört | dördüncü | fourth |
| beş | beşinci | fifth |
| altı | altıncı | sixth |
| yedi | yedinci | seventh |
| sekiz | sekizinci | eighth |
| dokuz | dokuzuncu | ninth |
| on | onuncu | tenth |
The vowel harmony rule in brief: back unrounded (a, ı) → -ıncı; back rounded (o, u) → -uncu; front unrounded (e, i) → -inci; front rounded (ö, ü) → -üncü.
examples in context
common pitfalls
Inserting "ve" in compound numbers. Turkish compound numbers are written and spoken without any connector. yüz yirmi üç is correct; *yüz ve yirmi üç is not.
Wrong vowel-harmony variant of -(I)ncI. Match the suffix vowel to the last vowel of the stem. üç contains ü (front rounded), so the ordinal is üçüncü, not *üçinci.
Pluralising the noun after a numeral. When a cardinal number is present, the noun it modifies does not take the plural suffix. Say üç kitap, not *üç kitaplar.
Doubling the vowel on vowel-final stems. When the cardinal already ends in a vowel, the initial I of the suffix is dropped. iki → ikinci (not *ikiinci); altı → altıncı (not *altıı ncı).
Forgetting t → d softening in dört. Before a vowel-initial suffix, the final t of dört voices to d. The correct form is dördüncü, not *dörtüncü.
Three sentences, graded here. Nothing is saved and no account is needed.
Okulun kütüphanesinde ___ kitap var. (250)
Fill in the blank with the correct Turkish number. Write the number in words.