用正反疑问形式提问

This is a way of asking a question by repeating the verb or adjective and inserting '不' (not) or '没' (not yet) in between, forming the pattern 'A 不 A' or 'A 没 A'. It is similar to questions like 'do ... or not?' in English. This form is used to ask in a neutral way, without leaning toward any answer. For example, with the verb '吃' (eat): 你吃不吃包子? (Do you eat baozi or not?). With the adjective '贵' (expensive): 这本书贵不贵? (Is this book expensive or not?). The 'A 没 A' form is usually used for whether an action has happened or not, as in '他去没去图书馆?' (Has he gone to the library or not?).