Returns the local language identifier (ID) of the language that is currently being used.
Transact-SQL Syntax Conventions
To view information about language settings, including language ID numbers, run sp_helplanguage without a parameter specified.
The following example sets the language for the current session to Italian, and then uses @@LANGID to return the ID for Italian.
SET LANGUAGE 'Italian'
SELECT @@LANGID AS 'Language ID'
Here is the result set.
Changed language setting to Italiano.