half-hearted ⇒ 他工作三心二意的。 Tā gōngzuò sān xīn èr yì de. → He's half-hearted about his work.

wholeheartedly

change one's mind

be nervous and flustered ⇒ 遇到这种麻烦事,他心慌意乱,不知所措。 Yùdào zhè zhǒng máfanshì, tā xīn huāng yì luàn, bù zhī suǒ cuò. → When he comes up against this kind of problem, he gets nervous and flustered and doesn't know what to do.

be disheartened

in all sincerity