Learn Spanish (Latin America): Mis viejas pertenencias las he guardado en el ático. - My old belongings, I have stored in the attic.

When you move a direct object like mis viejas pertenencias to the front of a sentence to set it as the topic, Spanish grammar requires you to double it with a matching object pronoun. Since the belongings are feminine and plural, we use las right before the verb.

Is it grammatically correct to drop the las and just say Mis viejas pertenencias he guardado en el ático?

No, that would sound broken in Spanish. If a specific direct object comes before the verb, the matching clitic pronoun is mandatory. However, if you use the standard word order and put the object after the verb, you drop the pronoun and simply say: He guardado mis viejas pertenencias en el ático.

Why is the adjective viejas before pertenencias instead of after?

Placing an adjective before the noun gives it a more subjective or emotional tone. By saying mis viejas pertenencias, you are emphasizing your personal history or nostalgic connection to these items. If you said mis pertenencias viejas, it would sound more objective, simply distinguishing your old stuff from your new stuff.

Since mis viejas pertenencias and las are feminine plural, why doesn't guardado change to guardadas?