The Spanish verb atender ("to serve," "to see to," "to attend to," among other uses) is a common source of confusion since it doesn't always mean what it sounds like it should to English speakers. Let's see some examples.
The verb atender meaning “to serve” or “to attend” can be very useful in any context that involves providing or receiving a service:
Quisiera saber si la doctora Castaño me podría atender hoy.
I would like to know if Doctor Castaño could see me today.
Caption 9, Cita médica - La cita médica de Cleer
Most of the time this verb is accompanied by the preposition a, but not always. In the following example, the preposition a was omitted:
Por el momento ustedes se pueden ir un rato a hablar con sus amigos, a atender [a] la visita...
For the moment you can go for a while to talk with your friends, to serve your guests...
Caption 40, Cocinando con Miguelito - Pollo sudado
This can be done because the expression la visita is depersonalized. But it's very different when the object of the verb atender is an individual or group of individuals, in which case you must always use the preposition a:
Mi ocupación es atender a la gente.
My job is to serve people.
Caption 67, Perdidos en la Patagonia - El Aeropuerto - La Sala de Esperas
The omission of the preposition a occurs more frequently when the verb atender means "to respond to," "to meet," "to answer to," or "to look after" something. For example:
Por ahí lo llamo, se da cuenta que soy yo, no atiende el teléfono.
I might call him, he realizes that it's me, he doesn't answer the phone.
Caption 47, Yago - 10 Enfrentamientos - Part 6
Y de pronto los que atienden [un] negocio...
And suddenly those who look after a business...
Caption 10, Festivaliando - Mono Núñez - Part 12
You always need to use the preposition a before atender when it means "to pay attention.” In the following example, Raquel uses the contraction al (a + el):
No tendrás dudas si atiendes al contexto de lo que se dice.
You will have no doubt if you pay attention to the context of what is said.
Caption 14, Raquel - Diminutivos y aumentativos
The verb atender is also frequently combined with personal pronouns (used instead of direct and indirect objects):
Voy a tratar de dejarme que me atiendan, que me hagan lo que necesite.
I am going to try to let them take care of me, do to me whatever I need.
Caption 23, Transformación - Estética
It's also common to reiterate the object of the verb in these expressions, even when a pronoun has already been used. For example, it's not incorrect to say dejar que me atiendan a mí (let them take care of me). Saying Es mejor que el doctor la atienda a ella primero is as correct as saying Es mejor que el doctor la atienda primero (It's better if the doctor sees her first). Here's an interesting example:
No sé, como nervios [de] que lo atiendan a uno y sentirse tan bien atendido.
I don't know, like nerves that one is taken care of and to feel so well taken care of.
Caption 20, Transformación - Estética
¡Gracias por atender a esta lección!