I don't quite understand what you said last night at a party.I think you might not like some of the words that I speak to you.I understand what's wrong.
I do not understand what you said last night at a party, I think you might not like some of the words I say to you that night, I could not understand what to do.
I don"t quite understand what you said last night that the party.I thought you might like some words that I say to you that night.I must have misunderstood.