英语翻译你要明白你的不足是什么.英语怎么说.口语化 书面化 都要/其实我想说 you need to know what

首先你那句话是有问题的,应该改为
you need to know what you are short of.因为what you are short of是know的一个宾语从句,从句要用正常语序.我个人觉得最简洁的说法是：you should know your weakness.无论是口语还是书面都可以.英语很灵活的,为什么一定要用一个形容词去表达呢?用一个现成的名词更简洁,而且很通俗易懂.另外你要用scarce是不对的,因为scarce常指物品稀缺,不能用于指人有弱点.

You must understand what's your shortage.
scarce 是作表语的，跟在be动词和系动词之后如
I could look for a job nearer to home,but I love my work and new jobs are scarce.

你那个是口语 书面的 You should be clear aware of your disadventages.
scarce 一般是指物品的稀缺，不指人
Smiles, unlike sandwiches, might be scarce in the snow this year.
微笑，与三明治不同，在今年的雪景中或许很稀缺。

you should know your shortcomings
you shall figure out what is your shortage
scarce形容词 a.
1.缺乏的;不足的[F]
Food and fuel were scarce in this region.
这地区食物和燃料都很缺乏。
2.稀有的,珍贵的