He definitely does sing "kanske är jag kär i dig", although the later one is just "kanske är jag k-". I think the phrase really sums up the whole idea of this song; him being in love with someone and therefore making a fool of himself and talking about stuff that doesn't really matter. I also think it adds credibility that the line is in Swedish. It could sound somewhat cheesy if instead of that he sang "maybe I am in love with you".
He definitely does sing "kanske är jag kär i dig", although the later one is just "kanske är jag k-". I think the phrase really sums up the whole idea of this song; him being in love with someone and therefore making a fool of himself and talking about stuff that doesn't really matter. I also think it adds credibility that the line is in Swedish. It could sound somewhat cheesy if instead of that he sang "maybe I am in love with you".