"I eat an apple and she eats bread."
Translation:Je mange une pomme et elle mange du pain.
I'm a little rusty, but here's my understanding.
"Je mange du pain." would mean "I am eating some bread," or "I am eating bread". It is not specifying what loaf of bread, just saying that some bread is being eaten. "Je mange le pain." would mean "I am eating the bread," and may be used if someone were asking you about a certain loaf.
I.E. Clare: I bought bread today. (Je suis acheté du pain aujourd'hui) Ben: I'm sorry, I ate the bread. (Je suis desolé. J'ai mangé le pain.)
Je mange, tu manges, il mange. http://konjugator.reverso.net/konjugation-franzosisch-verb-manger.html