Spanish language Q&A Forum

Hello, my question is regarding the use of “les” for “you” rather than “you all”.  It makes sense to me to use “le” for the formal usted and then “les” for the formal “you all” but I was never taught to use “les” for a singular person. The example I am referring to is: 

Señor López, le entrego el paquete.

"le llamo" should be accepted, no?

Missing word - Don't pay for those for him, or Don't buy those for him, maybe?

Hola,

Why do we only conjugate -ar verbs in the preterito indefinido tense? What about -er and -ir verbs?

Also, is the preterito indefinido the same as the simple past tense?

Gracias

I don’t understand any of this at all, whatsoever. I’ve read it many, many times, including the comments. I know there is a difference between Spain Spanish and Latin American Spanish for has/have, but how can one differentiate between them? I am so lost. 

Does querer que trigger the subjunctive if it's something you're wishing for yourself? 

Miguel tiene una novia y tu tienes

demasiada ( incorrect answer).  The correct answer is demasiadas

Miguel has one girlfriend and you have too many.

Una novia is singular so why is my answer demasiada wrong.