This is very true and it's also something that I noticed, if you are fluent, people sometimes start speaking so casually that it's impossible to understand them. I sometimes say to my English-speaking colleagues: "Whenever you see me just smile and not, it probably means that I have no clue what you have just said." :)
I didn't know many of them. Maybe it actually makes sense to create a list of tools that make communication easier and share it in the form of article?