I'm not sure that what you described above is the best solution to your problem, but this will take the message and shove the words into an array:

    @words = split /\s+/, <DATA>
    print join "\n", @words, "";

    __DATA__
    How are you?
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That prints:

    How
    are
    you?
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Note that the last word contains punctuation. To remove punctuation, change the first line to:

    map { s/[\?\.\!]*//g; } (@words = split /\s+/, <DATA>);
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Update: Added bit about punctuation.

Update 2: Without a more thorough description or code to look at, a better solution might be to just replace common abbreviations with the full word. For example:

    $msg =~ s/\bu\b/you/g;    # Replace "u" with "you"
    $msg =~ s/\br\b/are/g;    # Replace "r" with "are"
    ...
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