It's all a bit waffly and vague and theoretical, not practical.
I think it's best to assume that the other person is human like you and is capable of feeling the same feelings and having the same needs.
"Love language"? What? Sorry, language is a means of communication, love language isn't different from any other type - if you can't understand your DP's "love" language, it's because you're not listening. You don't need to learn a new language, you just need to listen to what s/he's saying in the language you both use to communicate.