Ok:
filologie=singular no article
filologia=singular articulated
filologii=plural no article
filologiile=plural articulated
I study the philology of Hungary.
Studiez filologia ungară
I study philology of Hungary and Polon.
Studiez filologiile ungare şi polone
(Here "ungare" and "polone" are plural,because in romanian language the adjectives are according in gen,number and case whit the noun which determine.
minge albastră (blue ball)
mingi albastre (blue balls)
I study philology and chemistry.
Studiez filologia şi chimia
"ungurească",isn't correct.ungară