"The sandwiches were made today."
Translation:Los emparedados fueron hechos hoy.
There are so many translations for the word sandwich. Including thd word sandwich.
As the normal verb tense when using the present perfect tense, it is not pluralized, even if the subject and/or the direct object are plural. However, when it is part of the passive tense construction, as it is here, the past participles acts like an adjective, and must agree in number and gender with the passive subject.
Los mujeres han hecho los sandwiches hoy.
(active sentence, past participle is non-variable ... always ending in "o"
Los sandwiches fueron hechos hoy. (passive structure)