@Leemarie: I totally understand where you are coming from. My DH’s mothertongue is Arabic and his whole family naturally tends to lapse into it when together. MIL’s English is excellent for someone who learned it when she was in her late thirties.
I felt pressured by his family to learn Arabic even when we were dating. There were periods when it caused tremendous stress for me and on our relationship. Both Darling Husband and I had to learn that language is an intrinsic part of culture and presents a barrier that cannot be scaled easily. I started to almost resent the language, because for me it represented conflict, an unhealthy way to leverage control (by MIL), and isolation. Darling Husband and I both wish now that we had taken a different approach early on, because I was defensive and he was frustrated and it pretty much killed all motivation to learn it. Darling Husband and I worked it out, obviously.
When we got pregnant, Mother-In-Law was constantly yammering about how they would only speak Arabic to the baby, that the baby HAD to learn it as its first language, and how she would teach the baby to say swear words to me, and I wouldn’t know what it was saying, etc, etc. By the, I’d learned a few things about her and their family culture in general, so I smiled and ignored it. I did have some stress pangs about it, though! Turns out, she had cut us out by the time the baby was born (another story!) so it came to nothing. Darling Husband sings to our baby in Arabic, but he admits it would be VERY difficult to raise our baby bilingual since we only speak English in our home. Before the baby came, I think he thought he would try, but he actually rarely speaks to her in Arabic and doesn’t care anymore.
Wow, this is long! All this to say is that a lot of our issues with two languages stems from personality and culture issues. Hopefully your Mother-In-Law is less controlling than mine, but I think a lot of it stems from fear and helplessness. There are also generational factors to consider; its easier for our DH’s generation to embrace a new language than for their parent’s. You cannot separate language and culture.
All that being said, I think its a little ridiculous that your Mother-In-Law or anyone thinks its perfectly normal for you to commit to learning Spanish. Um, you don’t just “learn a language.” It is a LOT of hard work and dedication to become fluent in a new language. Its not like asking someone to visit more, help out the ILs, or whatever. I think you are perfectly within courtesy and reasonable expectations to stay with limited Spanish. As a PP said, in some relationships, its healthier to have LESS communication.
Apologies for the novel!