wèi bì
not necessarily
maybe not
kòng xué lái fēng wèi bì wú yīn
wind does not come from an empty cave without reason
there's no smoke without fire (idiom)
xiǎo shí liǎo liǎo , dà wèi bì jiā
being bright at an early age does not necessarily bring success upon growing up (proverb)
wèi bì jiàn dé
not necessarily
that's not sure