"She is not fourteen."
Translation:Ona nie ma czternastu lat.
I think not, the only way of saying the age is 'mieć ... lat(a)'. Literally 'to have ... years'
That is how you would say it in Russian. Both languages are similar, but don't try to translate everything word by word. It's a separate language after all.
Remember, statements about age require the verb mieć.
Why can't I write it without "lat" at the end? Like in the afirmative examples... Thank you
In none of the examples about age a version without "lat" is accepted... unless I am unaware of something. It doesn't make sense without it. If you say "Ona ma czternaście", I will ask "She has fourteen what? cars? horses? ants?"
The only situation I can imagine is a short answer to "Ile ona ma lat?" (How old is she, literally How many years does she have), but then you just answer "Czternaście" and that's it.