English question, please help.?

It really depends on who you are talking to and how smart you want to sound.

If you are talking to a teacher, professor or someone above you I'd definitely use first and last names. Especially with lesser known individuals such as Hayden here who is evidently a musician.

I know a Hayden. He's 2 years old and while he may think he's a musician and may be one in the distant future, currently he is decidedly not.

In this case you should use first and last names.

Most everyone will recognize names like Newton and Beethoven so it's not as necessary with famous or well-known people to use first and last names.

Now, if you're just talking to your friends - it's find to use a first or last name when referring to someone they know of.

And in English when referring to people you know personally- such as friends or family- it's common to use only first names whereas if you're referring to your teacher or superior you would say Mr. or Mrs. and then their last name.

Usually when it is refferring to someone well known or famous you should use their last name only to be more formal and if it is about a roandom person use their first name:)

Its not very sophisticated, but yes, for famous people like those, it is common for people to only use their last name (some people don't even know their first names).

You might want to stick with just first or last name because using their full name can get tiresome after a while. And it really depends on how formal you want to be because using their last name is kind of a more formal way of talking about a person. Using their first names suggests a familiarity with the person or persons your talking about. In short all three ways are fine but it depends on context. I hope this helps.

For famous people, its better to use their last name, its more proper and if you were to call them by their first name like "Isaac"...well lets just say there are many "Isaac"s in the world :P but while calling someone that is not famous, its better to use their first name :]

you generally refer to people you don't know with their last name. For example referring to Issac newton as just Issac casually is something you normally wouldn't do unless you knew him personally or you were in contact a lot for example school.