必须 bìxū HSK2 must Origin Definitions Defs Strokes Stroke Words Sentences Sents bìxū must · required 必 bì auxiliary must must; have to; required to; be required to须 須 xū auxiliary must must; have to; shouldbìxū essential 必 bì adverb certainly certainly; surely; inevitably; necessarily须 須 xū auxiliary must must; have to; should