I repeated the task more than 10 times and stil wrong please need to check the o/p to get the exact error as I see there is no error from my side
The trick with this one is to use the word boundary match which is \b. This will find all occurrences whether surrounded by whitespace, punctuation or start/end of line
sed 's/\band\b/for/g' BSD_REPLACE.TXT
Can’t recall if it requires to change AND as well as and, but if it does, then the sed expression ends with /ig