Here's a breakdown:
Acceptable:
* Formal settings: You can use "Dear" in a formal letter or email addressed to a man. For example, "Dear Mr. Smith," is perfectly acceptable.
* Informal, close relationships: If you have a very close relationship with a man or boy, you might use "Dear" in a very affectionate way, like "Dear John." This is more common in writing than spoken language.
Generally avoid:
* Formal situations: Avoid using "Dear" in casual conversation with a man. "Hey John" or "John, how are you?" would be more appropriate.
* Unsure of the relationship: If you don't know the man well, it's best to use a neutral greeting like "Hello" or "Good morning."
Alternatives:
* Formal: "Sir" or "Mr. [Last Name]"
* Informal: "Hi" or "[Name]"
In Conclusion:
While not technically wrong, using "Dear" for a man or boy can come across as outdated or even a bit strange. It's better to stick to more neutral greetings unless you are in a very close and affectionate relationship.