read a book on grammar,then keep reading regularly-hopefully well written material will rub off on you.
Your original question, as an example, read: How do avoid mistakes when communicating online forum?First, watch for spelling errors (to, instead of do in the original question).Second, used complete...
Some mistakes to avoid are: Not looking at the interviewer Not turning off your phone Not waiting to be acknowledged before having a seat.
The word his can only be maid a grammar mistake if spelled wrong or capitalized
The girls IS here. I do not know NOTHING.