"No, those machines are not good."

Translation: Ne, ty stroje nejsou dobré.

[JessicaPaq9]

Why does this not work?
Ne, ty stroje nejsou dobrá.

[Jamie08MD]

Stroj Is a masculine inanimate noun and the adjective (dobrý) has to match the ending with it. So you get masculine inanimate nominative plural ending "dobré".

[AbhiBernammers]

"Ne, nejsou ty stroje dobré." was marked wrong. Why?

[svrsheque]

the word order is a bit odd. i added it anyway.

[filigree2]

The sentence "Ne, ty stroje jsou nedobré" was marked incorrect.
Is it incorrect to negate "good" instead of "is"?

[endless_sleeper]

It's very, very unusual. Nedobrý (though such a word exists) sounds kinda Newspeak-ish, like English 'ungood.' You should negate the verb instead.

[boydphil]

"Ne, ty mašíny nejsou dobré." Why is this wrong?

[VladaFu]

mašiny, not mašÍny Diacritics is important.

"Ne, ty mašiny nejsou dobré." is accepted.