CPAN to the rescue...

From Lingua::StopWords:

use Lingua::StopWords qw( getStopWords );
my $stopwords = getStopWords('en');
   
my @words = qw( i am the walrus goo goo g'joob );
    
# prints "walrus goo goo g'joob"
print join ' ', grep { !$stopwords->{$_} } @words;
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From Lingua::EN::StopWords:

use Lingua::EN::StopWords qw(%StopWords);
  
my @words = ...;
  
# Print non-stopwords in @words
print join " ", grep { !$StopWords{$_} } @words;
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