Editing Consonant cluster (section)

== Origin ==
Some consonant clusters originate from the loss of a vowel in between two consonants, usually (but not always) due to vowel reduction caused by lack of stress.<ref>{{Cite journal|doi = 10.1017/S0022226714000486|title = Syncope, syllabic consonant formation, and the distribution of stressed vowels in English|year = 2015|last1 = Polgárdi|first1 = Krisztina|journal = Journal of Linguistics|volume = 51|issue = 2|pages = 383–423|doi-access = free}}</ref> This is also the origin of most consonant clusters in English, some of which go back to Proto-Indo-European times. For example, {{angbr|glow}} comes from Proto-Germanic *glo-, which in turn comes from Proto-Indo-European *gʰel-ó, where *gʰel- is a root meaning 'to shine, to be bright' and is also present in {{angbr|glee}}, {{angbr|gleam}}, and {{angbr|glade}}.

Consonant clusters can also originate from assimilation of a consonant with a vowel. In many Slavic languages, the combination mji, mje, mja etc. regularly gave mlji, mlje, mlja etc. Compare Russian {{lang|ru|zemlyá}}, which had this change, with Polish {{lang|pl|ziemia}}, which lacks the change, both from Proto-Balto-Slavic *źemē.{{citation needed|date=December 2023}} See [[Proto-Slavic language#Alternations|Proto-Slavic language]] and [[History of Proto-Slavic#Iotation|History of Proto-Slavic]] for more information about this change.