The Past Participle as Adjective

Past Participles are verbs pretending to be adjectives. For example: With the resultant state structure of Estar with a past participle and the passive voice structure of SER you can see that the past partiple, which is the predicate (descriptive characteristic) of the subject, changes to show gender and number, just as does any adjective:

• Las galletas son hechas por Juanita todos los días, y son comidas por los niños. Esta mañana las galletas fueron comidas de una vez, y ahora están comidas.
  The cookies are made by Juanita every day, and they are eaten by the children. This morning the cookies were eaten right away, and now they are all eaten. [none are left]

Past Participles can be used as true past partiples with the helping verb HABER to form the compound or perfect tenses. When this is the case, they do not reflect gender and number because they are not actually functioning as adjectives. For example:

• Lo he visto. = I have seen it.
• No había estado allí antes. = I hadn't been there before.

Notice that these always end in [O]