Here's your problem: 
 my ($present_1,$present_2,$present_3,$present_4,$present_5) = $verb;

[download]
I assume you want all of the variables to be initialized with $verb. Howevr, this statement only sets $present_1 and the rest will be set to undef.

A quick fix is to write: 

 my ($present_1, ...) = ($verb) x 5;

[download]

Another approach to this would be to first compute the verb stem and then just add the appropriate ending: 


  my $stem = $verb;
  $stem =~ s/er$//;

  my $present_1 = $stem . "e";
  my $present_2 = $stem . "es";
  ...

[download]
For your group 1 verbs, this can be very compactly written: 
my @present_endings = qw(e es ons ez ent);
my @present = map { $stem . $_ } @present_endings;
...etc for the other tenses...

[download]
In fact, you might be able to make use of the module Lingua::Stem::Fr.

In reply to Re: Automatic verb inflection script by pc88mxer
in thread Automatic verb inflection script by gojippo

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.