Re: How to say this in Cantonese

I am also just a student so maybe the below is not perfectly correct, but this is how i would explain it.

You can say: 有啲DVD 有書面語嘅字幕，有啲有口語嘅字幕。你哋有冇口語字幕嘅DVD?

If they are still not getting it, you can try the below
大多數人哋寫嘅嘢同講嘅嘢唔一樣呀嘛。我要搵一隻DVD佢地講嘢同字幕寫嘅嘢係一樣嘅。