Vous invitez des amis les jours de fête? Oui, je les invite.

Question

Is it correct?

Accepted Answer

Hi Vera Maria, 
I am afraid I agree with your teacher.
Vous buvez souvent du café ? ---> Oui, j'en bois matin, midi et soir = Do you drink coffe often? --->Yes, I drink some morning, noon and night 
As-tu du pain? --->oui, j'en ai = Do you have any bread? yes, I have some
Vous avez de la farine ? --> Oui, j'en ai beaucoup = Do you have flour? yes, I have a lot (of it )
Vous avez des amis en France ---> Oui, j'en ai plusieurs = Do you have friends in France?  Yes, I have several of them.
In these cases 'en' replaces the partitive du, de la, des. 
Les will be used if you know specifically what it replaces -
Tu vas inviter Juan et Martin? Oui, je vais les inviter = Are you going to invite Juan and Martin? Yes, I am going to invite them
Tu invites les voisins? Oui, je les invite = Are you inviting the neighbours? Yes I am inviting them
Hope this helps!

Answer

Yes, sounds perfect.

Answer

Is it possible "Oui, j'en invite"?

Answer

My French teacher insits that "Oui, je les invite" it is wrong. For her, "Oui, j'en invite" it is the correct answer! Who I am going to believe?

Answer

Oui, je les invite is correct, because inviter needs a direct object and that is les and not en. There's one way I can imagine en to come into play:Vous invitez tous vos amis? -- Non, j'en invite un.(Do you invite all your friends? -- No, I invite one (of them).

Answer

I stand corrected.