In phonology, the tsâÂÂch merger is the merger of the voiceless alveolar affricate and the voiceless postalveolar affricate .
In Russian, it is the merger of the consonants rendered by letters Che and Tse. If the shift is towards Tse, it is called (); the shift towards Che is called (). Both pronunciation features are found in some Northern Russian dialects.
It is a regular sound change of Lower Sorbian, but not Upper Sorbian, as seen in the difference between Lower Sorbian and Upper Sorbian , both meaning "time".
In Polish the merger is part of a more general dialectal feature called (mazuration), present in many Polish dialects but named after the Masovian dialect.
It also occurs in a few areas of the Chakavian dialect of Serbo-Croatian, known as tsakavism.
The sabesdiker losn feature of Northeastern Yiddish includes the merger.
Greek-speaking people may merge (and ) into (and ) when speaking foreign languages that contain those sounds.