A lot of times native speakers aren't very good teachers of their own language. Native speakers often don't have a technical, or, should I say, a logical understanding of their own language. They just know how to speak it because they have grown up with it. For example, in the west we don't have "object markers" or "topic markers", so when we ask native Japanese speakers to explain particles like は, が, を, in a way we can easily understand, the native Japanese speaker might not have the tools or the vocabulary to do this. Frustrating for both of us, because it seems so simple.
Also, the native speaker might not be aware of the completely different use of language by a foreign person. If I go back to Musicisgood's thread where he asked how to say, "I need a driver's license", this was a very good opportunity to try to write it himself using a dictionary and some vocabulary he already knows, and then asking his wife to correct it. HOWEVER, his wife might not be prepared to explain how/why Japanese grammar works the way it does, and so it could end up being stressful for both.
For instance, like Bentenmusume said, the Japanese translation will depend on the context: are you asking for a license, or are you explaining something about a license? Are you asking a friend? Or are you at the counter of the local driving exam office? The words and phrases you use will probably change depending on the situation. It's not as simple as overwriting the English words with Japanese words. Already this might be too complicated for Musicisgood's wife to dive into. Or, it could be ground that has been well-travelled in the past, and she might not want to get into it again.
Japanese language forces you to make judgments about status and roles and education, in a way that isn't required in the west.
1. I need a license.
2. I would like to have a license.
3. If its OK with you, could you possibly grant me a license.
4. So sorry to bother you, it appears that I might need to have a license, so even though I know its a very busy day for you, could I humbly beg of you the huge favor of granting me a license?
Its easy enough to translate the first one into English, but it ends up being a very elementary statement; crude, abrupt, childlike (perhaps), and maybe even rude. It gets the point across, but my wife would cringe if I said something the wrong way. She would always push me for the 4th version - the most polite, but most complicated and taxing version. People without an understanding of all of this context might just say, "just give me a direct translation of #1", but in the real world of adults, that #1 version needs to be handled very carefully, and its a lot of work for native Japanese speakers to explain all of this. But first, English/Western speakers need to be aware that the use of the language reveals things about themselves.
Going back to PatPaul's original post: I wonder if they have patched things up. In the heat of argument, our partners can be pretty rude, and they can say hurtful things. Maybe its time to make a commitment to the language, and don't allow yourself to make any excuses. Set aside an hour a day to learn Japanese, or to learn kanji. Set yourself a goal of hitting a certain level of the JLPT test (I will pass the JLPT4 this year, or something like that). Trying to pick up Japanese by osmosis only works for infants.