Tu sei is for a singular interlocutor, obviously doesn't work with ragazzi (plural). "Granda mierda" (merda, not mierda) is singular and doesn't even make sense in the context. It would be something like: Ragazzi di Sherdog, siete pezzi di merda.
Your second sentence should be: Mi chiamo Oliver e non parlo bene l'italiano. No clue what you're saying after that.
You wouldn't pass the beginner class 1 final exam. Verb tenses for essere and knowing how to introduce yourself properly is something you cover in the very first classes. You didn't study 5 years. Sometimes people say stuff like that and you can clearly see they haven't progressed. Why? Because their idea of studying is spending like 1 hour per year studying. You're essentially a beginner and would need to start from scratch.
Why siete ? Does siete mean are ? As in Ragazzi of sherdog are ? Pezzi is pieces ?
Edit : siete is the plural of you. Voi siete, you are. Funny how english it's you are singular and you are for the plural. Also funny in Croatian it's vi ste which is the same as calling someone sir you are. English doesn't have calling someone sir without saying sir. German does have it. Sie as opposed to du. But Sie also means she and the plural third form aka talking bout others. Confusing. Also German and Croatian both got different words for animals and humans eating. Jesti, essen = eat. Žderati, Fressen - animal way of eating. Though maybe devour could be close to if or is it.
The word mad doesn't exist in German and Croatian. Mad is basically between angry and crazy. Closest would be wild as in wild, same spelling but different pronounciation. German and english are from the same language tree.
And I still can't speak italian tu mierde de la sherdog. We got italian tourists where I'm from in Hercegovina, for religious purposes. And you can see Italy from some points of the Croatian coast. Neighbours by water.
Gonna check if it's true, but do I remeber 15% of all Croatians can speak Italian. We actually are related. We're just majorly slavic but also mediterenian.
Yeah it's true some 14%. I'm not one.
And there's some areas where the population is mixed, just small parts. Like Italians in Croatia. I think we stole Pula from them, it has a coliseum.
Venecian republic used to be in Dubrovnik or something.
Well neighbours anyways.
If we were just slavs we wouldn't get brown in the summer. And have these funny nose and head shapes. And black hair.