摘要：to have an idea, a plan, etc. that will give you an advantage in a particular situation and that you keep secret until it is neede
have a(an) card/ace up your sleeve
有锦囊妙计；留有一招；胸有成竹；心中有数
to have an idea, a plan, etc. that will give you an advantage in a particular situation and that you keep secret until it is needed
字面意思为“有一张卡片藏在某人的袖子里面”，指某人做某事“心中有数，胸有成竹”。
Bill always has a card up his sleeve, so when his first plan failed he tried another.
比尔经常留有一手，所以当第一个计划失败后，他就试行第二个。
I still have a card up my sleeve that you don't know about.
我还留有你不知道的一个绝招。
If all these methods would not work, I still have a card up my sleeve.
如果这些方法都不管用，我自有锦囊妙计。
I'd been doing some quiet investigating in the meantime and had an ace up my sleeve.
与此同时，我不动声色地展开了调查，掌握了一张王牌。
Tom had an ace up his sleeve.
汤姆备有锦囊妙计胸有成竹。
The company has been struggling financially, but the CEO has a card up his sleeve. He's planning to launch a new product that could turn things around.
公司在财务上一直处于困境，但首席执行官有锦囊妙计。他计划推出一款新产品，可能扭转局势。
Tom always has a card up his sleeve, so whenever faced up with a puzzle, he could find a way.
汤姆总有锦囊妙计，所以任何时候遇到难题，他总能找到方法解决。
He always seems to have a card up his sleeve. Just when we think he's out of options, he surprises us with a brilliant solution.
他似乎总是有锦囊妙计。就在我们以为他没有办法时，他用一个出色的解决方案给我们带来了惊喜。
She always appears calm and composed, but I suspect she has a card up her sleeve. I wouldn't be surprised if she has a secret plan to win the competition.
她总是看起来很冷静，但我怀疑她有锦囊妙计。如果她有一个秘密计划来赢得比赛，我也不会感到惊讶。
The negotiator was well-prepared and had a card up his sleeve. Just when the other party thought they had the upper hand, he revealed a crucial piece of information.
谈判代表准备充分，都留有一招。就在对方认为他们占了上风的时候，他揭示了一个关键的信息。
Well, I still have a card up my sleeve. Let me share another idea with you.
那好，我仍有锦囊妙计，让我给您展示另外一个想法吧。
I've researched the company thoroughly and I have a good idea of what they're looking for. I feel like I have a card up my sleeve.
我已经彻底研究了这家公司，我知道他们想要什么样的人。我觉得我有备而来。
I have a few more cards up my sleeve.
我还暗藏了几招。
have/know sth off pat
having a ready-formed plan
be on top of things
be well-prepared
have a clear plan in mind
have an ace/tricks up one's sleeve：有铺囊妙计，留有绝招
I still have an ace up my sleeve that you don't know about.
我还留有你不知道的一个绝招。
I have a ready-formed plan for the next stage of the project， and I'm confident we can deliver on time.
我对项目的下一阶段已经胸有成竹，我相信我们能够按时交付。
I've been studying this topic for years， and I have a clear plan in mind for my research.
我已经研究这个话题多年了，我对我的研究有清晰的规划（胸有成竹）。
If I know Mark he'll have one or two tricks up his sleeve.
如果说我还算了解马克，我知道他总会留着一两招。
【情景对话】
A:Do you think Tom can remain at the top of the class this time?
A:你认为汤姆这次还能保特全班第一吗？
B:I believe so. He seems to have a card up his sleeve.
B:我相信他能。他看起来胸有成竹。
A:All his confidence comes from hardworking.
A:他的自信源于他的勤奋。
B:Yeah. he's the most diligent student I have ever met.
B：是啊，他是我见过的最勤奋的学生了。
来源：翅膀英语