Language File in Child Theme

I have upgraded to responsive DP 5.8 which apparently solved the issue of using a language file within a child theme. However, I still cannot get my child theme to use a custom language file.

I have tried to create _language.php in the child theme folder and in a new folder called framework, under the child theme folder.

The only way I was able to get an alternate language file working was to upload a language_alternate.php file in the main DP theme folder: wp_content/themes/DT58/templates/template_directory_theme/language_alternate.php

I’m worried that I will have to reinstall this alternate language file with every update.

Can someone tell me the exact location and file name to use so that a language file can be used within a child theme in responsive DP 5.8?