つまり君は何が言いたいんだ? What exactly do you want to say?
つまりあなたは私の意見に反対なのですね。 That is to say, you are against my opinion.
あなたは試験の結果が基準に満たなかった。つまり残念ながら落第だ。 The result of your exam failed to meet the required standards. In other words, I'm sorry to say you have failed.