It's not my evil intention to write, to post and to answer you in English. The point is that I see lots of people on this forum have real troubles to read English, especially those who work with Computer and want to become "Lap Trinh Vien" -also developers. But Computer with its OS (WINDOWS or LINUX or ANDROID) and its tools (incl. OOPL like JAVA, C/C++/C#/PYTHON/etc.) does not speak Vietnamese at all. And when you make a mistake or issue a wrong command Computer is very unforgiving. It throws back an ERROR MESSAGE onto your face.
Guess what language it throws back? YES, it's in ENGLISH.
A developer who cannot read a plain error message in English is like a blind who tries to drive a car and is wondering why he or she hears a lot of shouting and crying. I intentionally communicate with you in English. Most of you welcome my move and that is a very good sign and very encouraging (for me.)
However, I have a plea: Please don't apologize for bad English. I really don't care anything about grammar or wrong words. If I don't understand I can ask, can't I? And if you ask me openly to correct your English, I'll do.
I know a lot of Vietnamese who are American or French or German and live for years in the States (e.g. Orange County/Calif), in France or in Germany, but their command of English (or French or German) is unbelievably bad. The reason is easy to point out: they never try to speak the language of the country where they live. Their social environment is Vietnamese, with Vietnamese (like in a ghetto). Their children grow up at twilight world: They are neither Vietnamese (because of school and school buddies), nor American, nor French, nor German (because of their accented language). And that is a very sad, a very sorrowful fate for the youngsters when they later on have to look for a job or to work with the locals.
Break the mental prison. Get out the imaginary awe. (Talk and) Write and read in English (with me.) No excuse. That's the real world you're living. It isn't the world of rural backwater, is it?