Spanish is thus assimilated to the rest of the languages of alphabetic writing, in which only simple letters are considered letters of the alphabet, although in all of them there are combinations of graphemes to represent some of their phonemes.
In so many alphabet lessons it can be found the ch and ll digraphs, but they were put out from the spanish alphabet since 2010 cause that's what they are, digraphs, a pair of characters used in the orthography of a language to write either a single phoneme (distinct sound).
Sources:
Ortografía del español (wikipedia)Exclusión de ch y ll del abecedario (RAE)
