语言翻译文件PHP-自动

How I can translate very much values automatically- to aother language

For example:

en.php

$lang['activities'] = 'Activities';
$lang['add_item'] = 'Add Item';
$lang['add_payment'] = 'Add Payment';
$lang['add_task'] = 'Add Task';

to

de.php

$lang['activities'] = 'New Translation';
$lang['add_item'] = 'New Translation';
$lang['add_payment'] = 'New Translation';
$lang['add_task'] = 'New Translation';

Thank you