'to be spot on with something' - what does it mean?
Could you explain the meaning of the following expression: 'to be spot on with something'?

Question

Answer

It means to be perfectly correct.  "You were spot on with your guess."  You can also use "Your guess was spot on" or "you were spot on".

"Her work is always spot on" means what she does at work is always exactly what is needed.

I think Ramsha was thinking of "to be caught red-handed", which has nothing to do with being spot on. If you're caught red-handed, it means you are in the middle of committing the crime when you are discovered.

Answer

To be exactly correct.

Eg:
"What's the capital of England?"  
"I think it's London."    
"Spot on!"

Answer

to caught a red hand