use strict;
use warnings;
use feature 'say';

my $sentence = "this is the text to play with";
my $ngramWindow_MIN = 2;
my $ngramWindow_MAX = 3;

my $word  = qr/(\b\S+)(?:\s|$)/;  # "word" is $1, rather
my $ngram = join '', 
    $word          x   $ngramWindow_MIN, 
    qr/(?:$word)?/ x ( $ngramWindow_MAX - $ngramWindow_MIN );

my $re = qr/$ngram(?{
    say "@{^CAPTURE}"
    
# or do anything with @words i.e. @{^CAPTURE}
    
})(*F)/;

$sentence =~ /$re/g;