IF statements typically don't end in a semicolon (perhaps never? I can't actually think of a use case), but rather a curly brace, which must be matched after the block to be executed:
<?php
if ($some_condition ) {
some_action();
}
?>
If you're escaping from PHP to do plain HTML in the course of the block:
<?php
if ($some_other_condition) {
?>
<span>This is my HTML stuff here</span>
<?php
}
?>