Cách sử dụng
The expression "which is which" is used when you have two or more things that look very similar, and you are trying to distinguish between them. For example, if you have two identical cups, but one has coffee in it and the other has tea in it, you may ask "which cup is which?" to find out which is the coffee cup and which is the tea cup. This phrase is commonly used when you need help differentiating between two or more things that are confusingly similar.