Is it rude to call a teacher by their first name?

Answer 1

The right correct and perfect answer would be ........not really but if your talking to a complete stranger on the street yes

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Answer 2

It is a sign of respect to refer to a teacher with a salutation (Mr., Mrs., Ms., Miss, Dr., etc.). Referring to a person by their first name is more of a sign of familiarity among peers. So calling a teacher by his or her first name is indicitive of a closer relationship than most people have with their teachers and typically is not preferred, although not necessarily forbidden, in a school-type setting.