The literal translation would be “学习中文有趣而又欢乐。”, but since "fun" and "interesting" are close in meaning, you can also write: “学习中文很有趣。”, which is more concise and natural.

Hi Charlie, Literally, you could say “学中文好玩又有趣”, which is a statement. And if you particularly want to emphasize the present perfect tense, though in this situation you don't have to, you may say "学习中文的过程，好玩又有趣", translated as "The process of learning Chinese is/was/has been both fun and interesting". If I were you, I would say "跟你/您学中文，（我觉得）好玩又有趣" as I wanted to thank the teacher, emphasizing the time with her.

Mmmm... I guess so.. But I'd like to incorporate "has been" and "both" in the sentence... Not just "really interesting", and, in my mind "fun" and "interesting" is not the same thing - but I guess it is more so in Chinese? Since you're studying Swedish, I don't want to say "Lära mig kinesiska [är/var] verkligen intressant", jag vill säga "Det har varit både roligt och intressant att lära sig kinesiska", there's quite a differense. :)

Du kan säga 学中文真有意思。

It has been both fun and interesting learning a little Chinese. 這是描述狀態 : 學一點華語 既有趣 又引人入勝 fun 和 interesting 翻譯都作 好玩的 / 有趣的 甚無分別 但 interesting 有使人感到趣味 / 激發興趣 之意 故譯作 : 引人入勝 也可譯作 : 令人著迷 學一點中文 讓人覺得有趣 又令人著迷