Meaning of yǐ wéi:
yǐ wéi
以为
Verb
to think (i.e. to take it to be true that ...) (Usually there is an implication that the notion is mistaken – except when expressing one's own current opinion.)
Wǒ yǐwéi tā huì lái cānjiā jùhuì.
我以为他会来参加聚会。
I thought he would come to the party.