I am so lucky? Didn't accept it.. I don't understand.. Heureusement means luckily, doesn't it?
lucky = chanceux
happy = heureux
luckily = par chance
fortunately = heureusement (also used to mean luckily)
I can hear "si" very clearly, but the first syllable of "heureux" is a bit muffled, like "si-reux"
"heureux" is plural? "...eux" is there right? So how is it said in a singular context?
heureux is masculine singular and plural.
in feminine: heureuse, heureuses.
There are a good number of adjectives ending with -eux in singular: curieux, courageux, fameux, genereux... generally ending in -ous in their English translation.
There is the same nuance in meaning between "si heureux/so happy" and "très heureux/very happy" in both languages.