Wow! I'll admit I have not heard this exact expression in AE, but I have heard the term "smarty pants," and it is usually (though not always) used among children.
In AE, "smarty pants" can be used by and towards both men and women with no distinction. It is a name you call someone when they are acting or speaking in a sarcastic manner.
However, as I am not certain whether the "smart pants" you describe is the same as the AE "smarty pants," could you please give us a bit more context here?
I am also not certain if the usage among our BE-speaking friends is the same as that among AE speakers. Their "pants" are much different than ours!
Edit: I did a bit of googling. I did find a few references to smart pants that were about fashion and the use of certain materials in the making of pants (er, trousers to our BE bretheren) that help the pants maintain their shape after wearing. Is this what you are referring to?
I'm not sure a "smarty pants" is someone who speaks sarcastically-- you may be mixing in "smart aleck" here.
A smarty-pants is someone like me who thinks they know a whole lot about nearly everything. The proper time to call me by that name is when you've caught me, on the rare occasion, being wrong about something.
"Well, smarty-pants, since you know so much, maybe you could tell us why blowing out the fuel filter didn't fix the problem." (implying that I had said it would, and probably sounded pretty sure of myself)
Then I get defensive and say hey, I never said I was perfect. But people aren't 100% sure I really mean that. Plus, I'm getting a little smart-alecky too. Why don't we just check the next thing that might be wrong, like fouled sparkplugs, and quit worrying about who's right and who's wrong? Winning that argument ain't gonna get the car fixed.
Wow! I'm collecting a big amount of curious usage of the English language,
which, by the way, is a passion for me.
Whenever possible I like to insert some cultural notes to students. The
more you know a culture the easier it becomes to learn its language, and of course, spicy!
I think a smart-ass is a bit more objectionable than a smarty pants - and I don't mean just in the words used.
It is possible to use smarty pants with some element of affection and without being entirely insulting. You wouldn't want either of those characteristics to be associated with your use of smart-ass.
Thank you. I have read them. However I am still confused. I only indrestood that it is common in both BrE and AE. Could anyone makes the meaning clear. Posts said " Mr.Know it all". Then, is it ironic? Please make it more clear and if possible with examples
It does mean "Mr Know it all" and it is ironic, usually. We are more likely to say it when someone has said something that we think was just meant to show off how smart they are. However, between friends, for instance, it could be a joking way of complimenting someone on something they have said or done that showed intelligence.
It's sweetly ironic how the expression tells in a non-insulting way that either I have been proven wrong about something or shown to been very intelligent about something. I love the paradoxical use of expressions like that,and words too. :]