To have a secret plan or idea.
有一个秘密计划或想法。 (Yǒu yīgè mìmì jìhuà huò xiǎngfǎ.)
"Don’t worry, he has something up his sleeve for the project."
"别担心，他有东西在袖子里为这个项目。" (Bié dānxīn, tā **yǒu dōngxī zài xiùzi lǐ** wèi zhège xiàngmù.)
to impress or surprise someone greatly
to pause and calm down before reacting in anger
to work very hard to achieve something
to admit or confess to something you did wrong
to narrowly defeat someone or something
to refuse to change your position or opinion
