what is the hardest subject to lean? And how long did it take you?

[AJK13K]

Possibly, English and grammar.

I'm sure the other's you mentioned are also difficult.

Ditto

 

[pshufd]

Chinese Language - written, reading, spoken, listening. My wife picks up languages just by listening to people talking and interacting with them. I was teaching our kids Spanish and she was picking it up as I was teaching. Different people, different talents.