Gtranslate function with custom menu

I am very newbie with wordpress and editing plugins.

I have custom menu (English, Chinese (Simplified)) using html that I want it to call the gtranslate function for each language but it seems like it does not working. I dont know how to run the gtranslate with my custom menu.please help.

<li class="li-eng"><i class="sl-flag flag-usa"><div id="usa"></div></i> <span class="active"><?php _e('English', 'gtranslate'); ?></span></li>