Learn Hardcore Catalan: La mare està preocupada perquè la meva germana encara no respon. - My mother is worried because my sister still is not answering.

Breakdown of La mare està preocupada perquè la meva germana encara no respon.

Why is it la mare and not just mare?

In Catalan, it is very common to use the definite article with family members:

So La mare està preocupada is completely natural.

You usually drop the article when directly addressing the person:

So in a normal statement, la mare is the expected form.

Why does the sentence use està preocupada instead of és preocupada?

Catalan often uses estar for a temporary state or condition, and ser for a more permanent characteristic.

Here, preocupada means worried, which is a temporary emotional state, so està preocupada is the natural choice.

està preocupada = she is worried right now
és preocupada would sound unnatural here, as if you were describing worry as part of her essential character

So this is very similar to Spanish in this case.

Why is it preocupada and not preocupat?

Because the adjective has to agree with the person it describes.

Here it describes la mare, which is feminine singular, so the adjective must also be feminine singular: