"Hello boys!"

[languagelearner2]

why the les?

[Sitesurf]

In French, generalities use the definite article.

[annshoshkes]

what is a generality?

[Sitesurf]

it is when you mean something collective, valid for a whole group of people or things, like "men are strong", which means "in general, men are strong".

[Wonderclover]

Why can't you use des instead of les? I mean there's no the before the boys?

[Scherz]

I THINK it's because you're referring to the entirety of the group of boys you are addressing, and not just some of them. Could be totally wrong though.

[Jackie.Bowers]

Even if you're talking to the boys, you'd still say LES garcons?

[Sitesurf]

THE = LES