In Japanese, we agree if the speaker’s statement is correct. In English, we confirm the negative content of the statement. It can be quite confusing! I found a funny article explaining this ‘quirk’ here on Rocket News: ‘When “yes” means “no”.’
Ara! Gyuunyuu nai! Kai ni ikanakya.
Ah, there’s no milk! I’d better go and buy some.
Gyuunyuu nai tte?
We don’t have any milk?
*in English, we would say no. ‘No, we don’t have any.’ NOT ‘Yes, you are right, we don’t have any.’