In Vietnamese, we use nào to ask “which”.
Structure
Place nào after a noun to ask “which”. Its position in the sentence follows the placement of question words.
noun + nào
measure word + noun + nào
When the noun is understood from context, it’s acceptable to drop it and place nào after the measure word of the noun (only works if it has a measure word). This is like “which one” in English.
measure word + nào
Examples
- Anh chọn cái nào?
Which one do you choose? - Con nào nặng nhất?
Which one is the heaviest? - Chúng ta nên học ngôn ngữ nào?
Which language should we learn?
Usage notes
For the third structure, if there are more than one measure word, use cái as a middle-ground solution. For example, if option A is con mèo (“cat”), and option B is cuốn sách (“book”), then there is a conflict of measure words. Because of this, in this case, we have to use cái, so “which one” will be cái nào.
If a noun doesn’t have a measure word, then the first structure is the only option, of course. Otherwise, we have two options: either adding a measure word or not. However, there is a subtle difference between them: adding a measure word refers to each instance while omitting it refers to the general type of things.
- quả táo nào
which apple - táo nào
which variety/cultivar of apples
- cuốn sách nào
which book - sách nào
which genre of books