To handle multilingual menus, there are several options.

Module displayed only for a language 

Add a menu to a module and filter module by language

• Multilingual Module

Use language files to translate labels 

You can use the standard string translation process

• set your menu option name in admin-> menu in English
• set the user module title in the admin -> modules panel in English
• add in lang/your_language/language.php, the list on translations

But the URLs will not be translated. English should be the reference language, the same way it is the Smarty templates.

Check language and show alternate menu 

Here is an example, to be added to Site Identity

{if $prefs.language eq "en"}
{menu id=43 css=y type=horiz}
{else}    
{menu id=1 css=y type=horiz}
{/if}