#! perl -slw
use strict;

while( <DATA> ) {
    my @words = split /[^a-zA-Z']+/;
    for ( 0 .. $#words ) {
        printf "%s, $., %s %s %s\n",
            $words[ $_ ],
            $_ ? $words[ $_ -1 ] : '',
            $words[ $_ ],
            $_ < $#words ? $words[ $_ + 1 ] : ''
        ;
    }
}
__DATA__
little boy blue come blow on your horn
give a little, take a lot
give a lot, take a little
Mary had a little lamb
Don't belittle the little guy