He was unusually articulate for a ten-year-old.

I get the meaning "for" in this sentence. How "for" is used in it and the same other examples I want to know. Or something that maintains the context.
I'm not quite sure what you need. I assume you want more sentences with "for" in the meaning illustrated by your example sentence. But you say that you get the meaning, so you should be able to construct sentences like this on your own! It's harder than it seems at first, isn't it? Emotion: smile

He is rather quiet for a politician.
She is very clumsy for a ballet dancer.
She is pretty disorganized for an event planner.

He runs fast for an overweight man.
She spends a lot for a woman who claims to be poor.
He knows a great deal about astronomy for a self-taught man.

Students: Are you brave enough to let our tutors analyse your pronunciation?
kkk It was a bit fun of your gentle reproving comment at the begining of the answer.. Thank you for being not serious -- k

Actually I was not definitely sure , but 70~80%...

examples you made are awesome!!

Thanks, again.
Emotion: wink