Multi menu in Polylang

Hello
I’m not sure to well understand your question, but you can do that in Appearance > Menus > Manage Location tab. One dropdown per language and per location.

Ok thanks Chrystl, may be my english so bad.
Let me explain more detail i mean.
I use Polylang plugin to create multi language site.
I create menu header name: “menu_header” for Vietnames language and “menu_header_en” for english lamguage.
In header.php file i use code:

<?php
 wp_nav_menu(
      array(
          'menu'=>'',
          'container'=>'',
          'theme_location' => 'primary'
       )
);

Its work. I mean it can auto change language when i change language site.
Now ! I create menu footer name: “menu_footer” for Vietnames language and “menu_footer_en” for English language. And in footer.php file I use code.

<?php
 wp_nav_menu(
   array(
       'menu'=>'menu_footer',
       'container' =>'',
       'theme_location' => 'primary'
   )
);

It doesn’t auto change to english when i change language site to English.
What wrong. How can I fix it! Thanks so much !

I suggest that you read this: https://polylang.wordpress.com/2014/04/10/incorrect-usage-of-wp_nav_menu/