just 经常用作副词,表示仅仅,正好,刚才,只是.
eg:That's just what I think.我正是那样想的.
用作形容词是公平的意思
eg:You have received a just reward.你已得到了应有的报酬.
already 副词,指已经做某事
eg:You had already gone when I arrived there.当我到达时,你已经走了
yet 副词表还,仍然.
eg:He hasn't done much yet.他做的还不很多
用作连词表然而.
eg:She is vain and foolish,and yet people like her.她自负而愚蠢,然而人们喜欢她