Again you learned switch statements in JavaScript so look there for an explanation if you need it.  If not you should understand all of this as it is the same so put it into a page called  phpswitch.php and test it:

$month=8;

switch ($month) {    // switches replace multiple if statements and are neater but either way works
    case 1:            // if the variable matches the value after case then the next line(s) is/are executed
        $monthword="January";
        break;        // break stops execution and jumps to the end (otherwise all case statements will be checked which is slower)
    case 2:
        $monthword="February";
        break;
    case 3:
        $monthword="March";
        break;
    case 4:
        $monthword="April";
        break;
    case 5:
        $monthword="May";
        break;
    case 6:
        $monthword="June";
        break;
    case 7:
        $monthword="July";
        break;
    case 8:
        $monthword="August";
        break;
    case 9:
        $monthword="September";
        break;
    case 10:
        $monthword="October";
        break;
    case 11:
        $monthword="November";
        break;
    case 12:
        $monthword="December";    
        break;
    default:        // this is done if none of the others match
        $monthword="error";            
}

if ($monthword=="error") {
    echo "<p>There seems to be a problem with the month you entered";
} else {
    echo "<p>The month is $monthword</p>";
}            

You could now use PHP to get the actual current month int he first line fo code and show the word for that but as you can just get the month name that's probably a waste of effort!