Sentences
The personal a
A word that appears in front of people and does not translate.
When the direct object of a verb is a specific person, Spanish puts a in front of it. It carries no meaning of its own and there is nothing like it in English, which is why it is one of the last things learners start doing without thinking.
Examples
veo a AnaI see Anaa specific person, so the a appears
veo la casaI see the housenot a person, so no a
conozco a tu hermanoI know your brother
busco un doctorI am looking for a doctorany doctor, not a specific one, so no a
The mistake this causes
Translating it as to. It translates as nothing at all.