How do I get the language the user has selected?

I need to translate the text used in HTML/XML fields and there doesn't appear to be a way to do this via the normal methods. I therefore want to include an if statement within the HTML/XML to change the text, however I don't know the function for getting the language the user has logged in with (via the language picker). I'm not a coder at all, sadly, so please excuse me, but the logic I want is this:

get the users/sessions language

if language is french display 'bonjour'

if language is spanish display 'hola'

else display 'hello'

Thanks