Re: "What's the difference between..."

「呢兩種 ( or 兩樣) 有乜唔同?」
「呢兩種 ( these two kinds) 有乜 ( have what) 唔同 ( difference)」

**「呢兩種 ( or 兩樣)」 can be omitted if you point at the objects while you asking the question.