"They are not good."
Translation:Oni nejsou dobří.
I think i get it. In English, ¨they¨ is a perfectly good subject for the sentence, so it seems that ¨to¨ should work But in Czech, it¨s more subtle. ¨To¨needs to preceed an actual noun object, an actual word. Alone, ¨they¨ is far too general in Czech, it could refer to anything. You need to use ¨oni¨
Shouldn't the question have more context to know what "they" is referring to? If I'm the kitchen speaking to someone, I could point to bad fruit on a platter and say, "They aren't good." If that would that change the answer in Czech, then I feel the question should be expanded to include more context.
Hint: You will find that Czech is has much more flexibility with word order than English does. You will also find that the ability to re-order words in Czech sentences is not infinite or unrestricted. There are rules, and it can take longer than we'd all like to understand, remember, and follow them.
No, they differ in endings according to the grammatical gender. Please consult tips notes for more info. :)
-í = masculine animate plural nominative ending, plus there is a consonant shift as well dobrý > dobří
-é = masculine inanimate & feminine plural nominative ending
Scroll down for tips https://www.duolingo.com/skill/cs/Masculine
Not sure what you mean by "default". Sentences are entered manually and randomly are in masculine, feminine or neutral version. If it is a translation into Czech and it is not clear from the English sentence which gender it is, the system should accept all 3 genders.
If you use "je to", "jsou to", "nejsou to" and similar, you need a noun predicate (https://courses.dcs.wisc.edu/wp/grammar/category/predicate-nouns/). Nejsou to dobrá jména. Nejsou to dobří lidé. Nejsou to dobrá slova.
If you are speaking about some actual they and just describing them using adjectives, it is Nejsou dobří. Nejsou dobré. Nejsou dobrá.