I notice that when I speak to Japanese people (I live in Tokyo) that I subconsciously simplify and slow down my English, and even occasionally imitate their Eng

I notice that when I speak to Japanese people (I live in Tokyo) that I subconsciously simplify and slow down my English, and even occasionally imitate their English errors; but when I speak with other native English speakers I naturally pull out loads of slang and speed up significantly. I also notice that my friends don’t always do that naturally, and so my Japanese friends confide that they didn’t understand much of what my friends were saying. I wonder if I’m more attuned to that since my own parents weren’t native, 100% fluent English speakers (I definitely dumbed things down for them, too).