What are the biggest hurdles for those learning Japanese right now? Vocabulary doesn't count. It could be a particular grammar or the writing system for example.

Right now, my main problems are listening comprehension and the passive voice.

With listening, I just need more practice. I sometimes will have trouble with English listening comprehension too, so it's probably just my weakness. As a result I've gotten really good and reading and writing while my listening is still at an infant state.

It seems like the passive voice can be used a lot more consistently and logically in English than it can in Japanese. For example you will see the を particle with the passive voice sometimes. You also have grammar like たい form and the potential form which can be treated as passive but many times isn't. It's said that the passive voice conjugation has a nuance of regret, and yet it can also be used out of respect; however, I've seen it in cases where either of these nuances couldn't possibly be applicable. Perhaps it's just a piece of grammar to which I have to get accustomed.

What are you guys struggling with?