When I say jabłko, I remember яблоко and I feel like I'm saying the Russian one with something in my mouth that's preventing my tongue to touch the upper part of my mouth to make the л sound ;D ;D it's just weird hahaha
Yea, they are pretty similar, but the polish "jabłko" will look like "ябько" (or sth like that, coz everyone will read it different way)
You can ask me everything because I'm from Poland and I know this language. Don' t worry, even polish people ( children the most) have got many problems with their language.
yyes it is accusative, and it looks and sounds like nominative. this is the rule for all the neuter nouns.