This might work for you

#! perl -slw
use strict;

sub mapPairsN (&@) { 
    my( $code, $gap ) = (shift, shift); 
    map{ 
        local( $a, $b ) = @_[ $_, $_ + $gap ]; 
      $code->() 
     } 0.. $#_ - $gap; 
};

my @words = qw[ 
    The quick brown fox jumps over the lazy dog 
    and then fell head long onto the pond 
];

print "\nPairs with gap 1\n", mapPairsN{ "$a/$b\n" } 1, @words;

print "\nPairs with gap 3\n", mapPairsN{ "$a/$b\n" } 3, @words;

print "\nPairs with gap 5\n", mapPairsN{ "$a/$b\n" } 5, @words;

__END__
P:\test>333094

Pairs with gap 1
The/quick
quick/brown
brown/fox
fox/jumps
jumps/over
over/the
the/lazy
lazy/dog
dog/and
and/then
then/fell
fell/head
head/long
long/onto
onto/the
the/pond


Pairs with gap 3
The/fox
quick/jumps
brown/over
fox/the
jumps/lazy
over/dog
the/and
lazy/then
dog/fell
and/head
then/long
fell/onto
head/the
long/pond


Pairs with gap 5
The/over
quick/the
brown/lazy
fox/dog
jumps/and
over/then
the/fell
lazy/head
dog/long
and/onto
then/the
fell/pond
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