anyone

What is the difference between cualquien  and alguien?

¡Hola LinH-kuhe!

I think you mean to say cualquiera “anyone”?

If that's the case, here is the general difference: 

Alguien means “someone” in a statement and “anyone” in a question.

Cualquiera, on the other hand, means “anyone” in the sense of “anyone at all.”

Let me know if you still have any questions!

Saludos,

Liss

I don't understand the distinction you're making, sorry.  In the second example, what's the effective difference between “Do you know anyone here?” and “Do you know anyone (at all) here?”

¡Hola LinH-kuhe!

Sorry to be unclear! To sort this distinction out, let's approach the cualquiera vs. alguien issue from another angle.

When you use cualquiera, you are generally indifferent to who this person is. It could be anyone whatsoever. This is why cualquiera fits in the sentence Eso le puede pasar a cualquiera “That could happen to anyone”: we mean that it could happen to absolutely anybody. It doesn't matter who.

When you use alguien, on the other hand, then this sense of indifference isn't present. Instead, you're just talking about some unidentified or unknown person. That's why alguien fits in the sentence ¿Conocen a alguien aquí? “Do (you) know anyone here?”: we are asking about a person present who hasn't yet been identified.

Keeping this in mind, let's take a look at a couple more example sentences:

Es tan fácil que cualquiera puede hacerlo.
"(It) is so easy that anyone can do it."

¿Alguien me llamó?
"Did anyone call me?"

The first sentence once again has that sense of indifference — we mean absolutely anybody — while the second sentence is once again merely asking about an unidentified person. 

I hope that this helps to clear things up! Do let me know if you're still having trouble!

Saludos,

Liss