Slovak
In Slovak, ch represents /x/, and more specifically in voiced position. At the beginning of a sentence it is used in two different variants: CH or Ch. It can be followed by a consonant (chrbtica "spine"), a vowel (chémia "chemistry") or diphthong (chiazmus "chiasmus").
Only few Slovak words treat CH as two separate letters, e.g., viachlasný (e.g. "multivocal" performance), from viac ("multi") and hlas ("voice").
In the Slovak alphabet, it comes between H and I.
Read more about this topic: Ch (digraph)