BeholdPL

<?php
  
// menu
register_nav_menus( array(
    'main_menu' => __( 'Primary Menu', 'text-domain' );
  	// other stuff
);
                   
// primary menu
function registerPrimaryMenu() {

BeholdPL

<?php

function newWidgetsArea() {
  register_sidebar( array(
    'name'          => __( 'Stopka 1', 'text-domain' ),
    'id'            => 'footer-1-col',
    'description'   => __( 'Widgets in this area will be shown on all posts and pages.', 'text-domain' ),
    'before_widget' => '<li id="%1$s" class="widget %2$s">',
    'after_widget'  => '</li>',
    'before_title'  => '<h2 class="widgettitle">',

BeholdPL

<?php
  
// if WPML active
if ( class_exists('SitePress') ) {
    // stuff
}

BeholdPL

<?php

// if Polylang active
if ( function_exists('pll_the_languages') {
    // stuff
}