SAYING
I DON'T KNOW
The following expressions are casual andfamiliar. Depending on the tone of voice, they could be considered a bitsarcastic or rude. But often they are said in a moderate tone, and are simplyslangy （and very common） ways of saying Idon't know.
（It）beats me
You'vegot me
Searchme
I'mstumped
Yourguess is as good as mine
Ihaven't （got） a clue
I'mclueless
Ihave no idea
Ihaven't the faintest idea
Icouldn't （begin to） tell you
Ican't say
The expressions that follow are often saidwhen one doesn't know something and isn't interested in finding out, or whenone is disinterested and doesn't care to know. They're often said with adefensive tone of voice.
Whoknows?
Don'task me
Howshould I know?
Whyask me?
I DON'T KNOW
The following expressions are casual andfamiliar. Depending on the tone of voice, they could be considered a bitsarcastic or rude. But often they are said in a moderate tone, and are simplyslangy （and very common） ways of saying Idon't know.
（It）beats me
You'vegot me
Searchme
I'mstumped
Yourguess is as good as mine
Ihaven't （got） a clue
I'mclueless
Ihave no idea
Ihaven't the faintest idea
Icouldn't （begin to） tell you
Ican't say
The expressions that follow are often saidwhen one doesn't know something and isn't interested in finding out, or whenone is disinterested and doesn't care to know. They're often said with adefensive tone of voice.
Whoknows?
Don'task me
Howshould I know?
Whyask me?