Translation:My wife is American.
I was offered the choice of vocab which would have allowed "My wife is very drunk" which I think should be in the course
妻子 is more formal. Much more common is 老婆 and 老公 for husband. Can't believe they didn't put that in the course!
Or 太太. 老婆 and 老公 are rather crude and are more for street (colloquial) use. Use 太太 of you don't want to be too formal.
I know it's common usage, but I mildly detest that Duo Linguo isn't making a separation of the word American and "from the US" as that can mean anyone from both continents.
nobody use those formal words for husband or wife anymore, and if they do, they must be over 80 years old