Direct Object Pronouns

Remember that you use direct object pronouns when you don't want to keep repeating the direct object nouns.
Comemos tamales. becomes Los comemos.
We eat tomales. We eat them.

Llamamos al mesero. becomes Lo llamamos.
We called the waiter. We called him.

Note that the direct object mesero is a person, so it takes a personal a.

Also, not that a direct object answers the question what or who.

Direct Object Pronouns
me nos
te
lo/la los/las

Direct object pronouns are usually placed before conjugated verbs. They may also follow infinitives and -ndo forms, as well as affirmative commands.

When you put the pronoun after the infinitive or -ndo form, it attaches to the verb, like:
Lo vamos a llamar. becomes Vamos a llamarlo.
We're going to call him.

La mesera puso la mesa. becomes La puso.
The waitress set the table. She set it.