You will need to know a little about php to understand this tutorial. Just the basic would be fine.

Step 1 – Choose a domain

This would be the name for your translation. Usually I use the theme name as a domain. In this tutorial I will use my theme “Vanilla Globe” as in example. So the domain would be “vanillaglobe”.

Step 2 – Replace text with function

Inside the themes you will see text like

404 Error: Not Found

change the text into a function like this

<h2><?php _e('404 Error: Not Found','vanillaglobe'); ?></h2>

As you can see you will need to replace the text that you would like to translate with the function

<?php _e('text','domain'); ?>

Step 3 – Add __

Not only text, you would also want to have some parameters within the template tag to be translated. Example would be like

<?php the_content('Read more...'); ?>

add __ and the domain

<?php the_content(__('Read more...','vanillaglobe')); ?>

if there is more then one parameter, sample would be like this

<?php comments_number(__('No Responses','vanillaglobe'), __('One Response','vanillaglobe'), __('% Responses','vanillaglobe'));?>

Step 4 – Include the function

Open the header.php and at the very top include the code below

<?php load_theme_textdomain ('vanillaglobe'); ?>

This code is needed for WordPress to understand to use the language file that is inside the theme folder.

Step 5 – Build .po and .mo

Lastly, build the translation file in your language! You can look here to learn how to translate using poEdit. Make sure you have the files inside wp-content/themes/themename/. The name of the file should be the name of the language.