"about"means 关于guanyu 有关youguan eg.你能告诉我关于他的故事吗？Could you tell me the stories about him. 这是一本关于旅游的书。This is a book about travelling.

Sorry, put my answer in the wrong place. About means "關於" (guan yu2) or "有關" (you3 guan) in Mandarin. 我要告訴你關於這本書. But this sounds a bit unnatural. I would say 我要告訴你這本書的內容(nei4 rong2 content). "I want to tell you the content of the book" In this case, "about" is implied. What is this book about? 這本書是關於什麼的? This is book is about learning Chinese. 這本書是關於學習中文.

关于guan1 yu2

Hi Frank, sorry to contact here... i can' t find the way to send a message to you... are you looking for italian exchange? Thanks.

What sentence are you trying to express? Chinese is not English and sometimes, when English uses prepositions, Chinese does not.