One of the things I did this week was to research online English language tests. I also helped some Chinese friends with their English. Doing these things gave me insights into some of the peculiarities of English. For example, usage of small words like at, on, in, for, and phrasal verbs like get on, get off, put in, put up with, etc. must be particularly difficult to master, I imagine. It’s interesting to see your native language in a different light.
Many aspects of your native language are instinctive to you. Explaining them to others can be difficult – they just sound and/or feel right, but you aren’t necessarily sure why. The same is true for other skills – once you’ve mastered them, it can be difficult to remember how you learnt them, and you might feel that you have always been able to do them. For example, when I teach people juggling and other circus skills, I try to break every move down into small parts and to explain each in turn. Quite often I find myself wondering why things that I find very easy are so difficult for others. Then I remind myself that I’ve been doing these things a lot longer than my students.
My aim when learning other languages is to internalise as much as possible of the grammar so that I can use it without having to grope for the right inflection, gender, etc. With lots of exposure to a language, I eventually get a good feel for its structure. This enables me to speak and write it quite fluently.