Adjectives qualifying masculine nouns for human beings have nominative plural –í, accusative –ých:

Kde sú tí americkí študenti?

Where are those American students ?

Vidíš tých amerických študentov ?

Do you see those American students ?

Otherwise the nominative/ accusative plural is – é. Those is tie

To sú tie pekné domy.

Those are those nice houses.

Majú veľké autá.

They have big cars.

The rhythmic law operates in the same way as usual

Nie sú hlúpi.

They are not stupid.

Máme hlúpych kamarátov

We have stupid friends.

Deti nie sú hlúpe.

Children are not stupid.