May I refer to this thread :wink:
http://personalitycafe.com/istj-forum-duty-fulfillers/24454-what-your-love-language.html
To give a personal response, I think my primary preference of receiving affection would be quality time. It means
a lot to me if someone asks me to do something or they invite me somewhere - without there being any benefit for them other than my company. If someone does this with a pure intention, it's one of the greatest thing they can do for me.
Me showing affection would be acts of service. I enjoy being helpful to others with problems I specifically can solve. Like, if it's a computer or math problem and they have no clue themselves. When I care for someone I try and think of ways *I* can contribute with what *I* have to offer, because my practical abilities aren't that common and it boosts my self esteem to know that *I* have been helpful.