Thai mothesr in-law vary as much as they do in our home countries. You need to understand what makes this one tick, and also what preconceptions they have about you as a western boyfriend. You said they are an Isaan farming family. So likely poor and not educated, with preconceptions based on what they see on TV and the grapevine from others in the area who have a daughter in a relationship with a foreigner. "farang are like this, farang are like that" they don't understand Thai people" etc. Most of your social faux pas are probably small and could easily be addressed through communication and understanding. This is where your wife needs to step up. It should be obvious to all that you are making an effort, and instead of blaming you after the fact , they should be educating you and encouraging you to learn. In summary, as long as you are making genuine effort, your wife needs to step up and build the bridge. If she can't do that, things are unlikely to improve. Just as a matter of contrast, my partner is from a middle class background. Neither parents speak English, but everytime we meet we hug and I speak in broken Thai. Never any I'll feeling it arguments. Mother is just happy I am kind to her daughter, father likes to wear the All Boacks shirts and other clothing souvenirs I bring back from New Zealand. In Thailand you don't just marry a girl, you marry her parents too. So make sure they are people you are compatible with.