sub check_string($word) {
    foreach $chr (split //, $word) {
        $check .= $chr;
        if whole_word($check) {
            push @phrase, $check;
            $rem = substr($word, length($check), length($word) - length($check));
            check_string($remainder);
        } elsif not_valid($check) {
            @phrase = ();
            return;
        }
    }

        print "@phrase\n";
        @phrase = ();
}