This is the 208th most frequent Bulgarian word.
ч
The Bulgarian letter "ч" is the Cyrillic script equivalent of the English "ch" sound, as in "church."
In this sentence, 'често' means 'often', representing frequency, unrelated to the individual letter 'ч'.
Често чета книги.
I often read books.
In this example, 'че' is a conjunction translating to 'that', used to introduce a subordinate clause.
Той каза, че ще дойде утре.
He said that he will come tomorrow.
Here, 'ч' is used as a reference to the Bulgarian letter and its position in the alphabet.