Consonant Mutation

Changes in Spelling

In Turkish the spelling of the words is changed when the pronunciation changes.

Voicing of Consonants

Voiced consonant: Is one where the voice is used to produce the sound (soft consonants).
Unvoiced consonant: is where the voice is silent and only air is expelled to produce the sound (hard consonants).

The Equivalents are as follows:

Hard and Soft Letter Equivalents
p equivalent to b
f equivalent to v
ç equivalent to c
k equivalent to ğ
t equivalent to d
s no equivalent -
ş no equivalent -
h no equivalent -

Examples
köpek (dog) köpeğim (my dog)
bacak (leg) bacağın - (your leg)
topuk (ankle) topuğu - his ankle
bilek (wrist) bileğimiz (our wrists)

Spelling Changes to Suffixes

When adding a suffix which begins with a soft unvoiced consonant, it changes.

Example

-de , -da -> -te, -ta (in,on,at)
-den, -dan -> -ten, tan (from)

Mutation of Word ending in Hard Consonants

Note that the suffix reverts to its unvoiced form when added to words ending in an unvoiced consonant, this includes extended (suffixed) words.

Examples of Suffixes changing to Hard Form
kıtap (book) - kıtapta (in the book)
otobüs (bus) - otobüstü (it was a bus)
ilaç (medicine) - ilaçta (in the medicine)
sabah (morning) - sabahtan (from morning)
kibrit (match) - kibritten (from the match)