Asian Culture Shock: Can’t blame culture all the time

I don't know if anybody else has gone through this stage of culture shock - For a long while I buried language issues as the cause of most arguments in my marriage, in favor of cultural: after all, how could a missed past tense compare to the overbearing presence of mother-in-law. However, it slowly dawned on me that our problems were not so intractable. This wasn't the first time:
The wife was upset about work again – complaining about her boss.
“She shout at me,” she said.
“I'm sorry. Anyway, but she shouldn’t shout at you,” I replied.
“She shout me,” she said again.
I had no idea why she had just repeated the last sentence back to me again instead of engaging my point. However, I tried to keep my temper and repeated myself again.
“I know, but she shouldn’t shout at you - It is not professional.”
“No, she shout me. If she want.” She was herself angry at this point because she was sure she was addressing my point.
I lost my temper: “Are you listening? Why don’t you answer the point being put to you? - It is wrong to always shout at people.”
Now she exploded: “Why you don’t keep your temper? I think she can shout me - She is the boss.”
I was about to launch a tirade when I realized she had finally answered the question. I didn't agree that it was ok for bosses to shout, but at least she had answered the question. It was another 20 minutes spoilt because she had not added the word ‘can’ to the sentence. I wanted to shout at her again for getting the grammar wrong and wasting our time, but I decided to think about it first. Who’s fault was it that we had a language misunderstanding? I could speak Chinese better than her English but we had agreed to speak English at home to give her a chance to practice. As this was her request I kind of thought right was on my side. Still there was no point in saying anything.
What to do? Was I expected to second guess everything I heard? Was she expected to pay better attention to what she said? Ultimately, it was both our faults for assuming the worse of the other and digging in. Misunderstanding happened to people of the same culture but when you have a different language, it just added another dimension.
Unfortunately, another horrible truth occurred to me – Remember when we first arrive and are tripped up by the smallest grammar and accent issues from the Taiwanese speaking English, then as time passes we get used to it. You know we tell ourselves proudly that we got over communication problems because we had worked out what the Taiwanese wanted to say...Hmm, half the truth – We also got used to not communicating, to walking away when we were not 100% clear, and to arrogantly assuming we understood.
Oh, well. What to do? I took a good look at her. I resolved to pay better attention in future.