The language you choose as the session language does not affect your access to multi-language objects. For example, if you have user permissions to access a set of attributes and permissions to use the English, French, and Swedish languages, no matter which session language you choose, you will still be able to access the English, French, and Swedish values for those attributes. You can change the session language by logging out and back in, or if you are using the New UI, you can use the language selection dropdown on the far right of your dashboard's tool bar.
If you use the auto-translate field in the browser you are using to access EnterWorks and you select a language that is different from your session language, depending on the browser you are using, it will translate the text in your browser window to the language you selected, no matter what your EnterWorks session language is. Your browser will overwrite the EnterWorks UI text and display it in the language you selected for your browser to auto-translate to. For example, if your EnterWorks session language is Spanish, but you tell your browser to auto-translate to Polish, depending on how well your browser's auto-translate feature works, you will probably see all the EnterWorks text displayed in Polish.