my $var = "1 word here another word";
my($head, $tail) = $var =~ /( (?:\w+[ ]?){3} ) [ ] (.*)/x;

print "head - [$head]\n";
print "tail - [$tail]\n";

__output__

head - [1 word here]
tail - [another word]

##</code><code>##

print "yup" if "12 buckle my shoe" =~ /^\d{2}\b/;

__output__

yup