Is the following sentence correct grammatically?
'Sing to us, Mr. John!' shouted someone from the crowd.
[The event took place at a concert. Mr. John had such a nice voice that when he finished his show someone from the crowd shouted the sentence above.]
Is John his first name or family name?
But both are possible, Mr. Frodo.
When I worked in Oman, the students were required to address us as 'Mr John/Ms Marie/Dr Andrea'. I didn't like it, but that was the rule.