Originally Posted by Sarah Shaw-Gray
Well, we would like to consider ourselves less intellectually challenged, Sarah...
One very common mistake ESL students make with the phrase sore throat is that they replace sore with words like painful, achy, hurtful, etc.
Similarily, instead of saying a headache, they would say "my head is painful", "I have a sore head". Phrases like that need to be explained to them. These pharses remain fixed phrases or otherwise things begin to sound funny.