"She likes this soup."
Translation:Ona lubi tę zupę.
Well, I'd strongly recommend using Polish characters. If your keyboard is American, you can actually use Polish instead - it has everything in the same places, plus the special characters.
"ta zupa" is the Nominative case, mostly used for the subject of the sentence (Ta zupa jest smaczna = This soup is tasty). The verb "lubić", just like most of the verbs taught in the beginning of this course, takes Accusative. Which is "tę" for "ta" and "zupę" for "zupa".