dictionaries for LibreOffice

For whatever unknown reason aspell is not working well on my system. Like at all, spell-checking works fine only on Firefox because it has its own dictionaries obviously. In kwrite it works but only for some predefined dictionaries and I cannot add Bulgarian to it, even though I have aspell-bg installed. Oh well.
In any case, what helped in the end is downloading the dictionary for LibreOffice from:
https://wiki.documentfoundation.org/Language_support_of_LibreOffice
(for Bulgarian dictionary, go to:
https://extensions.openoffice.org/en/project/dictionaries-bg
for Spanish:
https://extensions.openoffice.org/en/project/diccionario-de-correccion-ortografica-separacion-silabica-y-sinonimos-en-espanol-espana)
Get the *.oxt files. 
And then from Tools->Extension Manager
You click Add and you add the dictionary you downloaded.
Note, you need to restart and also to change your dictionary by right-clicking and choosing Spelling and from the top of the window you choose your dictionary.
Happy spelling!