"Nu e a unsprezecea."

It must be femenin because of the first "a".

Masculin would be

Nu e al unsprecezelea

I think as the ordinal number is feminine, it must be referring to something feminine

What about this sentence tells me it's feminine? why can't it be "unsprezecelea"

Couldn't this sentence be "He's not the 11th"?

why this sentence look like feminine? Please explain if you don't mind..Thank you

I answered: It is not eleventh. (as if to answer the question, "Isn't your song eleventh on the top 40?") " It is not [the] eleventh?"

Why is "the" required? ...

I think as the form is feminine, it must be referring to something feminine, hence 'she'.