@OmSigDAVID,
Yes, they do, OmSigDavid... No se, is pronounced no say (means I don't know)... also hable (with accent) is ha-blay, mesa is may-sa... there are specific instructions on the pronunciation depending on where the e is in the word, and what follows it.
The x also has several pronunciations: if it occurs before a consonant, it's pronounced as a ks, as in mixto...
if it's between vowels, it can be pronounced ks or gz (examen and exiguo)
it it's at the end of the word, it is an x sound, as in dux, ...
and there are exceptions...
I got this all from the Berlitz English-Spanish dictionary, and my own experience from learning and speaking Spanish and travelling to spanish-speaking countries.
Different countries also have different pronunciations and even spellings, so it's much like English (tire/tyre, privacy/privacy)...