Remove consecutive duplicate words from a file using awk or sed

Question

My input file looks like below:

“true true, rohith Rohith;
cold burn, and fact and fact good good?”

Output shoud look like:

Answer 1

With GNU awk for the 4th arg to split():

$ cat tst.awk
{
    n = split($0,words,/[^[:alpha:]]+/,seps)
    prev = ""
    for (i=1; i<=n; i++) {
        word = words[i]
        if (word != prev) {
            printf "%s%s", seps[i-1], word
        }
        prev = word
    }
    print ""
}

$ awk -f tst.awk file
“true, rohith Rohith;
cold burn, and fact and fact good?”