1i. di cosa si tratta
e` simile a:
1e. what is it, what is it about ?
2i. dopo le infuocate lettere fra ambasciatori, adesso si tratta di una guerra
2e. after the furious letters (exchanged) between ambassadors, now a war is going to happen (the subject now is war)
3i. vuoi vincere una medaglia alle olimpiadi ?
qui si tratta di una cosa seria! Dovrai allenarti ogni giorno, ti auguro buona fortuna
3e. do you want to win a medal at the Olympic games ?
This is serious stuff! You should train every day, I wish you good luck.
4i A. (dal meccanico) mi ha guardato il motore ?
4i B. Si`, si tratta del cambio, un ingranaggio e` usurato, devo {cambiarlo, sostituirlo}
4e A. have you {seen, checked} the engine ?
4e B. Yes, it is the shift, a gear has been worn out, I must replace it
dal meccanico: 1. at the place where car engines, brakes, etc. are repaired, gets fixed,
or
2. talking to the person that does this job.
mechanic shop ? (I don't exactly know in English)
car repair shop ?