In general, bu is used to negate non-verbs, zero-valent verbs and monovalent verbs, while though fu is often used to negate bivalent verbs and trivalent verbs, bu can also be used to negate these two verb types.
In general, bu is used to negate non-verbs, zero-valent verbs and monovalent verbs, while though fu is often used to negate bivalent verbs and trivalent verbs, bu can also be used to negate these two verb types.
一般说来，非动词、零价动词、一价动词要用「不」来否定，而二价动词、三价动词常用「弗」来否定，但也可以用「不」来否定。