Example of how to change the EE taxonomy titles to 'Courses for {term}'.

tw_ee_theme_ee_archive_taxonomy_title.php

<?php //Please do not include the opening PHP tag if you already have one.

function tw_ee_theme_ee_archive_taxonomy_title( $title ) {
    if( is_tax( 'espresso_event_categories' )) {
        return 'Courses for ' . single_term_title( '', false );
    }
    return $title;
}
add_filter( 'get_the_archive_title', 'tw_ee_theme_ee_archive_taxonomy_title' );