Chouby on "[Plugin: Polylang] Howto change Footer content based on language in use"

The way you use is correct, except that you have syntax errors:

<?php $currentlang = pll_current_language();
if($currentlang=="fi"):?>
	footer content with lang 'fi' comes here
<?php elseif($currentlang=="en"):?>
	footer content with lang 'en' comes here
<?php endif; ?>

While developping, you should set WP_DEBUG to true.