"Señor, por favor espere acá."
Translation:Sir, please wait here.
Confused as well? Most of the answers I find say aqui and aca are: Yeah...they are interchangeable (mostly) It can be a regional It is based on location vs relative location to the speaker The only real clue I could find is that aca, as in this case, is more often associated with a verb. Please come here, Wait here etc... vs saying The food is here. We are here. Not a native speaker but that is my interpretation.
I thought I read that aqui tends to mean right here, whereas aca means over here (near, but not immediately adjacent)
I am still confused about formal and informal conjugations for commands. I recently saw for a different command verb that the -a ending is used for formal commands and the -e for the informal use of "tu." Can anyone shed light on this?
what is happening (I think!) is that the formal command forms are the third person subjunctive. So an -ar verb forms the formal is "espere". For -er and -ir it would be the opposite, the command form would end in -a. Google "spanish translations" and you will find a site that gives all the conjugated forms, helps me a lot to clear up stuff. I have been trying to figure out why the subjunctive forms are used for (formal) commands, but I guess they just are.