When to use
Nouns referring to people
Use the personal a before a noun that is a direct object when it is a person or a group of people.
Pronouns alguien and nadie
Use the personal a before the pronouns alguien and nadie. These pronouns, which mean someone and no one, or nobody respectively, must be preceded by the personal A when they are the direct object of a sentence and refer to specific people.
Use the personal a with non-personal direct objects to personify or humanize them. Some native Spanish speakers use the personal a when talking about cities, pets and a few other items, when they want to personify or make them more "human".
Use the personal a before country names that are direct objects of a verb.
Do not use the personal a if the country name is already preceded by an article.
If the noun (direct object) refers to a person, but is an indefinite noun, the personal a is not used. When there is no definite person involved, do not use the personal a.
The personal a is not always used with the verb tener. When the personal a is used with the verb tener, the meaning changes and implies that you have the person in a certain place.
Remember that the term "personal a" refers only to using the preposition "a" before the direct object of a verb. Remember not to confuse the "personal a" with other uses of the preposition "a" that often mean "to".