My son 5 yo is left hander, no problem for him to write in Chinese with proper stroke , his Chinese handwriting is nicer than his English. I am very strict on his bi hua, when he practices on his writing, I will make sure he writes correctly. For left hander, I only try to tilt the paper and I will always sit on his right so that I can see what he write. I think only writing the 毛笔字, will have the problem bc they will smear the ink… My girl is right hander, so when I coach both of them at the rectangle dining table, I will sit on the shorter side if the rectangle and both of them will on my left n right… So no issue…