Mr. (short for Mister) is a title you put before a man's last name as a sign of respect. You might address your teacher as Mr. Johnson or introduce your neighbor as Mr. Chen. The period after Mr. shows it's an abbreviation.

Using Mr. is a way of being polite and showing respect, especially when talking to or about adults. At school, you probably call your male teachers Mr. plus their last name rather than using their first names. When you write a letter, you might begin it “Dear Mr. Rodriguez.” In more casual situations, like talking with a close family friend, you might use their first name instead, but Mr. is a common polite form.

The title doesn't tell you anything about a man except that he's an adult. Unlike Mrs. or Miss, which traditionally indicated whether a woman was married, Mr. has been the same whether a man is married or single.

You'll sometimes see Mr. used playfully, like when someone jokes about “Mr. Fancy Pants” or when a child pretends to be grown up and calls themselves “Mr. Smith, Businessman.” But in formal writing and polite conversation, Mr. serves as a basic respectful way to address a man you don't know well or want to honor.