meaning of "on seat" and "at my desk"

i really want to know the difference between the two idioms.

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Originally Posted by adedamol

I really want to know the difference between the two idioms.

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'On seat" is not idiomatic. "at my desk" means "seated in front of my desk", probably working.

Quote:

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Originally Posted by adedamol

i really want to know the difference between the two idioms.

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I agree with bhaisahab, but I've never heard the term "on seat." Is this used in BrE?