Es cortés abrirles la puerta

[BobRitter]

Rosetta Stone has:

Es cortés abrirles la puerta a las personas que están detrá de ti.

I understand all but the abrirles. Is the les really needed?

Thanks, Bob Ritter, Pensacola, FL. USA

[chileno]

... to open the door (to them) = (les)

[aleCcowaN]

I would say it's almost indispensable. You may use "abrir la puerta" when they knock at your door, but I tend to think about it as an "open doors" policy, not the act of opening the door for them to come in. In this "for them" you have the seed of that "les". Think that we may only say "abrirles la puerta" and the action and its purpose is totally clear.

Also, in many cases we use "le/s" to depict the beneficiary of our actions, though it may be not strictly needed from the point of view of grammar.

[Luna Azul]

Yes, it is needed. It's the redundant pronoun used in Spanish to replace an IO even if you mention it.

[BobRitter]

Makes sense. The redundant pronoun concept takes a bit of getting used to. Thanks.