Your spouse must be fairly old school to be using a dialect that isn't mando/canto... Most millennials I know from mainland china and even Malaysia/Singapore w

Your spouse must be fairly old school to be using a dialect that isn't mando/canto... Most millennials I know from mainland china and even Malaysia/Singapore will speak putonghua with their parents/family now. Ofc people from Sichuan and Shanghai love to preserve their dialect. Plus you got the cantos and hokkien/teochew/hakka and even changsharen. In any case, my recommendation would be to stay with Mandarin and go deep on it. Learning a dialect afterwards is quite straightforward and you can be 80-90% proficient esp with understanding by just developing a sound mapping of each character from dialect->mandarin. The common idioms you'll pick up with enough exposure. You'll never regret learning Mandarin first - you'll be able to read/listen to the news and your relatives will understand you. Whereas if you try to learn dialect first you'll find it harder due to the less set of materials AND less people to talk to. A lot of chinese people joke that they learned their 2nd/3rd... dialect by doing KTV and there's definitely some truth in that