recursive function in php app with $_SESSION arrays - php

Question

Im trying to build an ap in php to learn foreign languages. I got an function in it that builds a form and starts the test. it looks like:
public function test($pol_ang)
{
$words = $this->wordsArray();
if($pol_ang == 1)
{
$_SESSION['correctAnswers'] = $this->answersPolAng($words);
}else {$_SESSION['correctAnswers'] = $this->answersAngPol($words);}
if(isset($_POST['btn-confirm']))
{
$answer = strip_tags($_POST['txt_word']);
if($answer != "")
{
$_SESSION['usersAnswerArray'][$_SESSION['licznik']-1] = $answer;
$_SESSION['licznik']++;
}
if($_SESSION['licznik'] > count($words))
{
unset($_SESSION['licznik']);
$this->auth_user->redirect('result.php');
}
}
if(empty($_SESSION['licznik']))
{
$_SESSION['licznik'] = 1;
}
?>
<form method="post" class="form-signin">
<table class="table table-striped table-hover">
<thead>
<tr>
<th><?php echo $_SESSION['licznik'].' z '.count($words); ?></th>
<th></th>
<th></th>
</tr>
</thead>
<tbody>
<tr>
<?php
$word = explode(";",$words[($_SESSION['licznik']-1)]);
if($pol_ang == 1)
{
?>
<td><?php echo $word[0]; ?></td>
<?php
}
else
{
?>
<td><?php echo $word[1]; ?></td>
<?php
}
?>
<td>-</td>
<td>
<div class="form-group">
<input type="text" class="form-control" name="txt_word" placeholder="Tłumaczenie" required />
<span id="check-e"></span>
</div>
</td>
</tr>
</tbody>
</table>
<hr />
<div class="form-group">
<button type="submit" name="btn-confirm" class="btn btn-default">
<i class="glyphicon glyphicon-log-in"></i> END
</button>
</div>
</form>
<?php
}
At the begginning wordsArray() function explode class's variable and $words becomes an array: [0]->wordLanguage1;wordLanguage2, [1]->wordLanguage1;wordLanguage2 etc...
$pol_ang is language option. If equals 1 then $_SESSION['correctAnswers'] becomes "wordsLanguage1", if equals 0 then becomes "wordLanguage2".
This function works fine. But what I wanna do is that my functio after ending the test should repeat asking for words that user entered incorrect. I can not find the solution to my problem