"El are douăsprezece mii."
Translation:He has twelve thousand.
That's the way english numerals are formed. "How many are they? Twenty-thousand." "Thirty thousand soldiers died in that battle" and so on and so forth. But you can say "thousands came to the wedding".
Well, there's a difference if I said "I have twelve thousand dollars" and if I said "I have twelve thousands of dollars"
we're using douăsprezece because mie is feminine? (aka doisprezece mii would be incorrect)
You are correct.
Douăsprezece mii de bărbați (twelve thousand men)
Douăsprezece mii de femei (twelve thousand women)
Thank you and thanks for all the help you give throughout the course, it's extremely appreciated.