Snobbish girl is correct but your question is not.
Written correctly, your question would be:
Is snobbish girl correct grammar?
Yes, it is grammar, but your spelling is wrong; it's spelt grammar.
Nick probably hates what all guys hate in a girl. If they are snobbish and rude. Its unattractive.
The noun form for the adjective snobbish is snobbishness.
Wrong grammar!
Snobbish does not have a prefix. Although, its suffix, is "ish".
'Snobbish' is an adjective meaning superior, arrogant, stuck-up, patronizing, condescending, snooty, and/or pretentious. Example - He acted snobbish when he was introduced to her.
Snobbish people are not usually well liked. She was very snobbish, acting like she is better than everyone else.
Wrong Grammar
nothing ! because your wrong grammar !
You were - This is correct. You were the best in the team.
yes
Her snobbish attitude was evident as she turned up her nose at the inexpensive wine served at the party.