In English, the definite article ‘the’ is only used if the specific referent has been previously mentioned or is otherwise clear from the context. And in English, the simple present action verb ‘eats’ is only used for the narrative present, or for habitual or regular action. So yes, in a context meeting both of these conditions, «La ragazza mangia il pane.» can also be translated as “The girl eats the bread.”. For example in the narrative present “The next morning, they find a house made of gingerbread. The girl eats the bread. Then…”; or in the generalization “For Sunday lunch, the prison always provides foccaccia and taleggio. The girl eats the bread. But she never touches the cheese.”.
In Italian, the definite article is used whenever the referent is specific, whether or not it's been previously mentioned or is otherwise clear from the context. So when referring to any specific instance without an explicit referent, even though in English you'd say “The girl is eating bread [right now].” or “[Next,] The girl eats bread.” in Italian you'd say «La ragazza mangia il pane.», because in a specific instance, the bread she's eating must be specific even if it hasn't been specified. Only in a generic statement about bread in general would you say «La ragazza mangia pane.» = “The girl eats bread.” without the definite article in Italian.
il = most masculine words
lo = masc. words starting with s+consonant, gn, pn, ps, x, y, z or a vowel
la = most feminine words
l' = any singular word starting with a vowel (contraction of lo/la)
il → i
lo → gli
la → le
l' → gli (masc.) or le (fem.)
So with some examples that's:
il pane → i pani
lo zucchero → gli zuccheri
la donna → le donne
l'uomo → gli uomini
l'arancia → le arance
Most masculine words end in -o and most feminine words end in -a. Hope I answered your question and a bit more for anyone else.
la ragazza = the girl
il ragazzo = the boy
le ragazze = the girls (specifically female)
i ragazzi = the boys/the children (both sexes)
The vowel usually tells a word's gender/number: -a for sing. feminine, -o for sing. masculine, -e for plural feminine, -i for plural masculine.
la ragazza → le ragazze
il ragazzo → i ragazzi
Just make sure to watch out for singular words ending in -e like lo studente.
If it were "The girls eat bread", both ragazza and mangia would have to change: Le ragazze mangiano il pane.
I said raggaza instead of ragazza and it still marked me wrong, but on others it just says 'typo'