"He is talking to the animal."
Translation:On mówi do zwierzęcia.
You can "rozmawiać" with someone if (s)he is talking with you. "Mówić" you can to everyone/everything or even to yourself. "Rozmawiać" assumes conversation.
Maybe this one will help you: "Rozmawiać" is connected with "rozmowa" (conversation) "Mówić" with "mowa" (speech)
Yep and they have the same meaning. We also use phrase "mówić coś pod nosem" - speaking too quiet to be understood by others.
Well, it also has an -a ;) But yes, as the Nominative is "zwierzę", I guess you have to call it an irregular one.
That's "He's telling the animal" and you'd have to specify what he is telling.