PHP查找单词是否包含在一个大数组中

我需要检查一个单词数组($words)是否存在于一个较大的数组($dictionary)中。如果所有的单词都在，就没有错误。如果$dictionary中没有包含一个或多个，我想发送一个错误消息。到目前为止，我已经想到了这个:

<?php
// first I select a column from a MySQL table and retrieve 
//all the words contained in that field.
$spell = "SELECT * FROM eventi WHERE utente='{$_SESSION['username']}'";
$qspell = mysql_query($spell) or die ("Error Query [".$spell."]");
while ($risu = mysql_fetch_array($qspell)){
    $risu = mysql_fetch_array($qspell);
    // the following lines remove parentheses, digits and multiple spaces
    $desc = strtolower($risu["descrizione"]);
    $words = explode(" ",$desc);
    $words = str_replace("(","",$words);
    $words = str_replace(")","",$words);
    $words = preg_replace('/[0-9]+/','',$words);
    $words = preg_replace('/'s+/',' ',$words);
    // the array $dictionary is generated taking a long list
    //of words from a txt file
    $dictionary = file('./docs/dizionario.txt',FILE_IGNORE_NEW_LINES);
    foreach($words as $k => $v){
        if (in_array($v, $dictionary)){
            //Do something?
        } else {
            $error = "error";
            echo "The word ".$v." can't be found in the dictionary.";
        }
    }
}
if (!isset($error)){
    echo "All the words are in the dictionary.";
} else {
    echo "There are some unknown words. See above.";
}
?>

此代码总是返回一个错误消息，而不报告找不到哪个单词。最重要的是，实际上缺失的单词不会被检测到。我做错了什么?