Questions & Answers about La almohada nueva es muy blanda.
Because almohada is a feminine noun in Spanish, so it takes the feminine article la.
A useful general rule is that many nouns ending in -a are feminine, and almohada follows that pattern:
- la almohada
- una almohada
As always, noun gender in Spanish is grammatical, so it has to match the article and any adjectives that describe it.
Because adjectives usually agree with the noun they describe in gender and number.
Here, almohada is:
So the adjective must also be feminine singular:
- nuevo → masculine singular
- nueva → feminine singular
- nuevos → masculine plural
- nuevas → feminine plural
That is why Spanish says la almohada nueva, not la almohada nuevo.