1. Exit from Portal with RTX
   
2. Go to Steam > LIBRARY > select Portal with RTX > click right mouse button on it
   
3. Choose Properties… > on General tab you must look at LAUNCH OPTIONS text box
   
4. On LAUNCH OPTIONS text box just type/or copy/paste -language
   Example:
   
   -language spanish
   This option will make the text language of the game menu and subtitles in German
   
   (including the user interface, for example the text with the inscription “Health”, as well as the names of weapons and everything else that the user sees directly in the game itself)
   
   
5. A little higher we have a line with a drop-down menu called Language; in Portal with RTX it only changes the audio language. You can select the desired audio language from this menu.
   
   
6. Go to Portal with RTX root install directory folder
   
   
   • Find game install directory:
     If you don't know where is your Portal with RTX install directory is located, you can open Steam main window, navigate to LIBRARY > Right click on Portal with RTX > select Properties… > LOCAL FILES tab > Browse… button
   
   
7. Find portal_rtx folder and open it
   
8. Find gameinfo text file > right click and select Open with > , then find and select WordPad
   
9. In gameinfo.txt you need looking for these strings:
   
   
   game_lv |all_source_engine_paths|portal_rtx/portal_lv.vpk game+mod |all_source_engine_paths|portal_rtx/portal_sound_vo_english.vpk game+mod |all_source_engine_paths|portal_rtx/portal_pak.vpk game |all_source_engine_paths|hl2/hl2_textures.vpk game |all_source_engine_paths|hl2/hl2_sound_vo_english.vpk game |all_source_engine_paths|hl2/hl2_sound_misc.vpk game |all_source_engine_paths|hl2/hl2_misc.vpk platform |all_source_engine_paths|platform/platform_misc.vpk
   
   
   • just add new string by Left click at the end of this textline:
     
     game_lv |all_source_engine_paths|portal_rtx/portal_lv.vpk
     and press Enter
     
     
   • Select and Copy this spaces and text
     
   • YOU MUST COPY THAT WITH ALL SPACES:
   
   
   game+mod |all_source_engine_paths|portal/portal_sound_vo_english.vpk
   
   
   
   • YOU MUST PASTE THAT WITH ALL SPACES
   • and Paste to your new empty string
   
   
   • You must have something like this example:
     game_lv |all_source_engine_paths|portal_rtx/portal_lv.vpk
     game+mod |all_source_engine_paths|portal/portal_sound_vo_english.vpk game+mod |all_source_engine_paths|portal_rtx/portal_sound_vo_english.vpk game+mod |all_source_engine_paths|portal_rtx/portal_pak.vpk game |all_source_engine_paths|hl2/hl2_textures.vpk game |all_source_engine_paths|hl2/hl2_sound_vo_english.vpk game |all_source_engine_paths|hl2/hl2_sound_misc.vpk game |all_source_engine_paths|hl2/hl2_misc.vpk platform |all_source_engine_paths|platform/platform_misc.vpk
10. In WordPad's window click on File > Save, then close the program
    
11. Select wanted language from context menu list:
    
    Select the language you witsh to play this game in:
    • English
      
    • Русский (russian)
      
    • Español (spanish)
    
    
    • For Français (french) and Deutsch (german) languages you need follow this:
      1. In properties of Portal with RTX you must select GENERAL tab and looking for LAUNCH OPTIONS
         
      2. Then type or copy:
         For Français (french):
         
         -audiolanguage french
         
         For Deutsch (german):
         
         -audiolanguage german
         
         parameter into textbox
      • You must have something like this example:

        LAUNCH OPTIONS
        Advanced users may choose to enter modifications to their launch options.
        

        -audiolanguage german

    
    This option will change all characters' voices to Deutsch, including your H.E.V. Suit.
    
    
12. On LAUNCH OPTIONS text box just type/or copy/paste +cc_lang
    Example:
    
    +cc_lang russian
    This option will change the language of all subtitles to Russian
    
    In conclusion, you will have a menu and interface language in German, a character voice language and H.E.V. Suit is in Spanish (if you selected Spanish in the language selection drop-down menu above) and the subtitle language is in Russian
    
    
13. This code can be combined like this:
    
    -language spanish -audiolanguage german +cc_lang russian
    
    
14. Below is a complete list of languages that are available in Portal with RTX.

[Source Engine] Change language for all supported games on Source]