Use this jQuery code:

    jQuery(document).ready(function () {
      jQuery('select#select-language').hover(function () {
        jQuery(this).attr('size', jQuery('option').length);
      }, function () {
        jQuery(this).attr('size', 1);
      });
    });



Add this Style to this select-box

    select#select-language {
        position: absolute;
        top: 3px;
        z-index: 2;
    }

There's also another **good solution**. You should convert `<select><option>...` to `<ul><li>...` list, and apply jQuery scipt as shown here in my answer : https://magento.stackexchange.com/questions/113941/display-the-drop-down-values-when-mouse-over-on-text-instead-of-textfield