Questions & Answers about Dobrá péče je pro dítě důležitá.
Because both adjectives agree with péče.
- péče is feminine
- it is singular
- here it is in the nominative because it is the subject
So the adjectives also appear in the feminine singular nominative form:
- dobrý → dobrá
- důležitý → důležitá
This kind of agreement is a basic feature of Czech grammar.
For English speakers, this can feel surprising because noun endings do not always match what you might first expect. In Czech, you often have to learn the gender together with the noun.
So it is:
- ta péče = the care
not - to péče or ten péče
That feminine gender is why the adjectives are dobrá and důležitá.