"A decade is not a second."
Translation:Dekada to nie sekunda.
It can be:
Dekada to nie sekunda. ("to" + "nie" + nominative)
Dekada to nie jest sekunda. ("to" + "nie" + to be + nominative). Here "to" is not necessary but it's not an error to put it.
Dekada nie jest sekundą. ("nie" + to be + instrumental)
Only direct objects of transitive verbs change from Accusative to Genitive in negations.
Yes, it is correct but maybe less common. You can see that there is "jest" in parentheses in immery's comment.
Ah, true. I think what confused me about your original comment was 'Here "to" is not necessary but it's not an error to put it.' - really that's not the case, it's "jest" that's optional in this case. Basically if you use "to", you don't have to worry about declining even if you also use być, but if you don't have a "to", you need to use the full być + instr. construction.
"normal sentences" :
dakada to nie sekunda
dekada to nie jest sekunda
dekada nie jest sekundą
rare: dekada nie jest to sekunda.
dekada to nie jest sekundą
Here "to" is used in a different meaning- it is an expressive particle. In this sentence I cannot think of context where it fits. but "A maj to nie jest miesiącem"?" ("And May is not a month?") or "A kobieta to nie jest człowiekiem?" (and a woman is not a human?)
I thought negations take the genitive case. So, " Dekada nie jest sekundy. " did not work?
you are right, but also only accusative changes to genitive.
"Dekada nie jest sekundą"- sekundą in instrumental
I agree that sekundą is instrumental. But now with "nie", doesn't sekunda become genitive -sekundy?
Apologies in advance for being so dense on this one. I've read through the comments but still not clear - Why is my answer of "Dekada to nie jest sekunda" rejected? I understand that dropping "jest" would be better, but does adding "jest" completely rubbish the sentence?
Actually if you use "to jest" instead of simple "to", that's still Nominative. Such a construction is more rare and we do not teach it, but we do add it if someone requests it. So added.