"Is maith liom tú go mór."
Translation:I really like you.
Even though 'you' is not really an object accusative in this structure? (~ you are good with me) So it's not like 'Feicim thú'. Or is it a regional thing?
Is go mór an adjective or an adverb in this sentence? (I've only seen it so far in the tree as an adjective, but it's translated here as an adverb).
It's not a proper English sentence. It would sound like you are saying "I like you! Really!" which is something you would say to someone when you are trying to convince then that you don't dislike them. "I really like you" means that your affection towards them is greater than they might realize.
So, tú is an object pronoun in this sentence, but Duolingo isn't teaching us to use "thú" here. Is this similar to who/whom in English, where there is the grammatically correct way of saying something, and then there is the often done and socially acceptable way of doing so? (For example, "whom do you like?" is more commonly phrased, "who do you like?")