I just try the system again and find it's only happen to word which short, which contain only 3-4 letter
Test system using 4 word :
rtoo as misspelled word of root --> shown no suggestion (also with "roto")
fier as misspelled word of fire --> shown no suggestion
danm as misspelled word of danb --> shown no suggestion
We find a fact :
- google give more accurate for brand names than abreviations. but google give more accurate for abreviations than general word.
- google suggestion system is start to run well if we're looking for 5letter or more word. For example : leaev as misspelled word of leave and hosue as misspelled word of house (at least it's shown sentences "Did you mean: house" )