I wish I could understand Japanese

Sure there are. On the top of my head...some simple words...

計：ji/jie
的 : de/di
還: hai/huan
了: le/liao

Keep in mind, that some Kanji have multiple sounds, but Japanese have their non Kanji characters. Chinese is totally in "Kanji".

For comparison, here are the Japanese pronounciations :

計：haka(ru)/kei
的 : mato/teki
還: kae(ru)/kan
了: ryou

I've no idea, but I've had some pretty strange experiences with English -> Japanese dictionaries. Mostly because it's kinda vague with it's translations. For instance, you look up something like "circular" and get two kanji for it. 丸 and 円. I've never seen 円, you probably won't be needing that one. But because your dictionary put it, you'll be using it assuming it's right.

円 is mainly only used for the Japanese currency. It's used for some other stuff, but en (yen) is its main purpose. Now that I think about it, 円 is used a lot... Maybe as much as 丸 is.