The word "brilliant", used here (almost only in British English), is synonymous with "great" or "excellent". While "brilliant" without any context, can certainly mean "ingenious" (and as an American English speaking native, that is the assumed meaning without any context), in this situation, "ingenious" does not work, as its meaning is restricted to mean "genius", "brilliant", "intelligent", etc.
I know it's particularly confusing in this instance, since Duolingo provides absolutely no context. However, even in my experience as an American English speaker, if someone exclaims "Brilliant!", I typically assume they mean "Great!" There exists an implied "That is" in front of the exclamation, so that the full meaning is really conveyed if you write, "[That is] brilliant!" The only exception would be (again, I can only speak on behalf of American English) if someone, for example, makes an ingenius scientific breakthrough. However, British English speakers may be more skewed towards the "Great!" meaning; most of my exposure to that meaning comes via British English speakers.
In American English, the word "brilliant" typically is not a stand-alone ejaculation. It is usually encountered in a full sentence, rather than with implied words as shown above. E.g.: "Einstein's theories of relativity were absolutely brilliant!"
I hope that helps.
Hi ZZyss, non ! les deux se prononcent et s'entendent de la même manière. La seule différence est le genre, masculin "génial" ex : J'adore ton frère il est génial. (masculin pluriel = geniaux) ou féminin "géniale" Ex : Tu as raison c'est une idée géniale. (féminin pluriel = géniales) Ou l'interjection génial ! (extra, super,formidable...) Ex : Génial ! il a réussi le concours. (Brillant in English)
- brilliant, great, fantastic (according to several dictionaries)
However, if you look it up in reverse, you could get up to several dozen answers! The reason is that "génial" is also an interjection meaning "great", so lots of words (many informal) can indicate that sense, like cool, awesome, sweet, super, superb, beautiful, etc. I think that's why there are so many comments here that ask what about this and what about that...
Why was "brilliant" rejected when it was taught as an option for génial?