During my time in grad school, teachers and visiting writers preached about the value of learning a second or third language. They often joked about a line spoken by a few writers in the past, "The best way to learn a language is in bed."
After more than a year of marriage, and two prior years together, I can assure you that this theory does not work. Jia is a great Chinese teacher--her students say so--but I haven't learned much from her. She has tried to teach me Chinese, I just couldn't retain it (unless it was humorous, pointless, or slightly crude). However, there have been a few times I've asked questions and remembered what Jia told me. Still, it's rare that I learn anything from my wife.
Now it's her turn. Jia wants to improve her English. Her spoken English is fairly good; it's the writing and reading skills that need work. I've given her a few books to review at home, but I haven't even attempted to give her any sort of lessons. I figure it works the same way for her as it does for me.
I've met plenty of people who have lived in China longer than I have and have the same problem with learning Chinese. They also seem to have similar problems with spouses. I have to wonder, is it possible to learn from a spouse?