You can access the language manager in the control panel by following the path:
Languages > Language Manager
You will see 2 options, Add New Language and Rebuild All Languages
When you press “Add Language” you will see the following form:
Title: The name of the added language.
Text Direction: Set the text direction either from left to right or from right to left depending on the added language, this choice will apply to the control panel and all the site sections.
Language Code: It is an abbreviation for the language name, will be used as a symbol for the language, for example: ar=Arabic, ar-sa=Arabic-Saudi Arabia
HTML Character Set: It is the value of the variable “charset” for contents of type HTML in “header” template.
Number Formatting: You can choose the decimal separator symbol, for example: Choose “.” to see the numbers like that “1.3”, if you want to use space as separator use “_”
Thousands Separator: It is the symbol used to group digits for example: 1,638,257, you can use space as separator by using “_”
Press “Save” to save changes.
This is used to rebuild all the phrases of every language in the language table to restore it to default after any modifications or additions to the phrases, also in case of any problem in the language table.