Consonant Assimilation

Level 1

When a word ends in a voiceless consonant (p, ç, t, k, f, h, s, ş), the first letter of the following suffix must also become voiceless (c → ç, d → t, g → k).

How It Works

In Turkish, consonants are divided into two groups: voiced (soft) and voiceless (hard). Ünsüz Benzeşmesi (Consonant Assimilation), also known as Ünsüz Sertleşmesi (Consonant Hardening), occurs when a suffix starting with a voiced consonant (c, d, g) is attached to a word ending in one of the eight voiceless consonants.

The eight voiceless consonants can be remembered using the mnemonic Fıstıkçı Şahap (F, S, T, K, Ç, Ş, H, P).

The Transformations:

d becomes t: Used in the locative case (-de/-da → -te/-ta), the ablative case (-den/-dan → -ten/-tan), and the simple past tense (-di → -ti).
c becomes ç: Used in the agentive suffix (-ci → -çi) and the manner suffix (-ce → -çe).
g becomes k: Used in derivational suffixes to form nouns like atkı (scarf) or seçkin (elite).

This rule is mandatory in writing and applies to numbers (e.g., 3'te), abbreviations, and proper nouns after an apostrophe (e.g., Sinop'ta, Mehmet'ten).

Exceptions: The rule does not apply across the boundaries of compound words (e.g., Akdeniz), in certain mathematical terms (e.g., üçgen), or with invariant suffixes like -gil (e.g., Özgürgil) and -cağız/-ceğiz (e.g., çocukcağız).

Examples (5)

Kitapta resimler var.
There are pictures in the book.
Word by Word: Book-in pictures exist.
The word 'kitap' ends in 'p' (voiceless). The locative suffix '-da' changes to '-ta'.
Dün akşam çok geç yattı.
He went to bed very late last night.
Word by Word: Yesterday evening very late he-slept.
The verb stem 'yat-' ends in 't'. The past tense suffix '-dı' changes to '-tı'.
Bu çocuk çok çalışkandır.
This child is very hardworking.
Word by Word: This child very hardworking-is.
The stem 'çalış-' ends in 'ş'. The suffix '-gan' (meaning 'one who does') changes to '-kan'.
Saat üçte buluşalım.
Let's meet at three o'clock.
Word by Word: Hour three-at let-us-meet.
The number 'üç' (3) ends in 'ç'. Therefore, the suffix '-de' becomes '-te'.
Sokakta kimse yok.
There is no one on the street.
Word by Word: Street-on anyone not-exist.
The word 'sokak' ends in 'k'. The locative suffix '-da' changes to '-ta'.

Common Mistakes

Forgetting to change the suffix in writing.
İşde çalışıyorum.
İşte çalışıyorum.
Since 'iş' ends in 'ş' (voiceless), the suffix must be '-te', not '-de'. Writing 'işde' is a spelling error.
Applying the rule to the separate conjunction 'de/da' (meaning 'also').
Ahmet te geldi.
Ahmet de geldi.
The conjunction 'de/da' is a separate word and NEVER changes to 'te/ta', even if the preceding word ends in a voiceless consonant.
Ignoring the rule with numbers.
1945'de
1945'te
1945 ends in 'beş' (five), which ends in 'ş'. You must apply the rule based on the sound of the number.

How It Connects

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Consonant AssimilationLevel 1

Learn This First

To learn consonant assimilation, you must first understand the Turkish alphabet to identify which consonants are voiceless. Additionally, since this rule is applied when adding suffixes, a basic understanding of vowel harmony is necessary to correctly form the complete suffix.

Vowel Harmony: Front and Back
Consonant assimilation usually occurs in suffixes that also follow vowel harmony rules, so understanding how suffixes adapt to the root word is essential.
Level 1

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