Should I learn a Chinese Dialect? Will Cantonese negatively impact my Madarin?

No, you should not learn a Chineses dialect if you don't live in China and use it. Otherwise, you will be confused. For example, if you learn Cantonese as a second language, it will negatively impact your madarin.

I can’t speak Cantonese. As a native speaker, I don’t think it will negatively impact my Chinese. Cantonese preserves some ancient pronunciations. The poems more than a thousand years ago, e.g., poetries of the Tang Dynasty, can be read aloud more forcefully with Cantonese.

I can speak only one dialect of Shandong Province where I live. I went to Beijing in January this year and saw a doctor. He asked me: '哪儿不好'? The sentence structure and accent were rarely used in my life experience, so I needed some time to comprehend. At the moment, the doctor became impatient and assumed that there were some problems with my intelligence.

But I feel difficult to distinguish any dialects of English. I can notice there's a difference between the accents in a movie. It usually has a story context. I have never been abroad and rarely hear real people speak English in China. I doubt that some of my English pronunciations are incorrect. I have used different textbooks over the years. Some of them give me British phonetic symbols, while others give me American phonetic symbols. I can't remember which one is British and which one is American. If you want to learn a Chinese dialect, you may be in a similar situation.

My American friends have told me that certain English accents can be challenging to understand. For instance, some BBC TV announcers are almost incomprehensible. Similarly, certain American English dialects can also be difficult to decipher.

In conclusion, it is best not to learn a Chinese dialect at the same time. Most Chinese people can't speak more dialects than their own dialect.