"对啊" 的英文表达是 "right" 或 "correct".

其来源是英语中的口语用语，表示赞同或认可对方的说法或观点。

下面是一些例句：

A: "I think we should finish the project by next week." B: "Right, let's get started on it right away."
A: "I heard that the concert is sold out." B: "Correct, it was sold out within minutes of tickets going on sale."
A: "I think we should take the highway to get there faster." B: "Right, that's a good idea."

对应的中文翻译为:

A: "我认为我们应该在下周之前完成这个项目。" B: "对啊，我们马上开始吧。"
A: "我听说那场音乐会售罄了。" B: "对啊，票一开售就被抢空了。"
A: "我认为我们应该走高速公路去那里。" B: "对啊，这是个好主意。"