Learn Hardcore Spanish (Latin America): Nuestras visitas son muy importantes.

In Spanish, nuestras must agree in both gender and number with the noun visitas. The noun visitas is feminine and plural, so we use the feminine plural form nuestras.

Why is visitas in the plural form here?

The word visitas refers either to multiple visits or multiple guests, depending on context. If you were talking about a single visit, you would say nuestra visita (feminine singular).

Why do we use son instead of están?

Ser (conjugated here as son) is used for inherent or more permanent qualities—something that defines the subject. Since the sentence states that these visits are very important (a defining, lasting quality), son is correct. You would use están to indicate a temporary state or condition.

Why do we say muy importantes instead of muy importante?

Adjectives in Spanish agree with the noun they describe in both gender and number. Visitas is plural, so the adjective importante must be made plural: importantes.

Could visitas also mean the people who are visiting, not just the act of visiting?

Yes! In many Spanish-speaking contexts, visitas can mean people who come to visit (guests) as well as the visits themselves. The exact meaning depends on context.