Ts–ch merger

In phonology, the ts–ch merger is the merger of the voiceless alveolar affricate /ts/ and the voiceless postalveolar affricate /tʃ/.

In Russian language it is the merger of the consonants rendered by letters Che and Tse. If the shift is towards Tse, it is called tsokanye (Template:Lang-ru); the shift towards Che is called chokanye (Template:Lang-ru).

It is a regular sound change of Lower Sorbian, but not Upper Sorbian, as seen in the difference between Lower Sorbian [cas] Error: {{Lang}}: text has italic markup (help) and Upper Sorbian [čas] Error: {{Lang}}: text has italic markup (help), both meaning "time".

In Polish language the /tʃ/ → /ts/ merger is part of a more general dialectal feature called Mazurzenie, after the dialect of Mazovia. It also occurs in a few areas of the Chakavian dialect of Croatian, known as tsakavism.

The sabesdiker losn feature of Northeastern Yiddish includes the /tʃ/ → /ts/ merger.