Rake someone over the coals

Todays English Assembly idiom is quite an interesting one rake someone over the coals.

 it means they criticize you very severely usually when youve done something wrong.

Lets make it easy to understand with some real-life examples.

Imagine your teacher finds out youve copied your homework from a friend. Uh-oh!
She calls you out in class and gives you a strict warning.
In that case, you could say
 

My teacher raked me over the coals for copying the homework.

Or imagine at home you come back late from a party without informing your parents.
When you reach home, they scold you badly for being irresponsible.
Then too, you can say
 

My parents raked me over the coals for coming home so late.

So, remember rake someone over the coals doesnt mean youre literally burning someone!
Its just a colorful English way to say to scold or criticize severely.