What if you immigrate and can't speak English?

If the purpose of your immigration is for your career and your own development, I suggest that you still need to learn English as a tool, so that you can truly integrate into the local society and develop your career better. If for other reasons, I suggest you learn English well, otherwise you will be very lonely, unless you are in the Chinese area, but the security environment there is not as good as the local middle class area.