Crysis 2 chooses it's language based off what your system is using at the time of installation. This can be overridden if you need to by doing the following:
1) Navigate to your main Crysis 2 directory and open the file called System.cfg (with notepad or a text editor)
2) At the bottom of the file should be "g_language = XXX" (where XXX is the default system language).
3) Navigate to the Localized directory: Crysis 2/GameCrysis2/Localized and here lists the available language packs you have installed. Also states in the sys_languages section in System.cfg.
4) Now you know which languages you can use and change to whatever is supported/installed (depending on region).
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Steam users: Right click on Crysis 2 in your Game Library -> Properties -> Language.
There you can chose you prefered Language.