| you can't put an old head on young shoulders |
you can't run with the hares and hunt with the hounds |
you can't say fairer (than that) |
you can't say fairer than that |
(you can't) teach an old dog new tricks |
| you can't teach an old dog new tricks |
you can't win |
you can't win them all |
you can't win them all（或win some, lose some） |
you can't（或can）（〈美〉 shouldn't 或should） talk |
| you could cut the atmosphere / air / tension with a knife |
you could cut the atmosphere with a knife |
you could have fooled me |
you could have fooled me! |
you could have knocked me down with a feather |
| you could have knocked me （或her, him, 等） down with a feather |
you could hear a pin drop |
you da man!, you're the man! |
you don't know |
you don't know when you're well-off |
| you don't say! |
you don't say（或you don't say so）! |
you, etc. can stuff sth |
(you, etc.) may/might as well be hanged/hung for a sheep as (for) a lamb |
you, etc. should be so lucky |
| (you) go, girl! |
you had me worried |
you have no idea (how / what etc) |
you have no idea… |
you haven't lived |
| you haven't lived (if / until...) |
you have to hand it to sb |
you have to laugh |
you have/you've got to laugh |
you / he etc alone |
| you, he, etc. can't win |
you, he, she, etc. started it |
you know |
you know / do you know |
you know something/what? |
| you know something （或what）？ |
you know who / what |
you know who/what |
you-know-who（或you-know-what） |
you live and learn |
| you'll be lucky |
you'll be sorry |
you'll only |
you'll thank me |
you'll / you'd be lucky |
| (you) mark my words! |
You may rely upon it. |
you may（或might as well）be hanged for a sheep as for a lamb |
you must be joking |
you must be kidding |
| you name it |
you name it (they've got it)! |
you need only do sth / all you need do is … |
you never can tell |
you never can tell / you can never tell |