The full list of questions and answers is here.Believe it or not, friendships are difficult to write in fiction. They can easily come across as forced, particularly if they involve too much explication and too many overt gestures of affection. People are both complicated and subtle, and often that subtlety is expressed in subconscious ways: as an exercise, pick out groups of people at a table in a restaurant or café or pub (although in pubs, booze can confound things), and try to work out relationships, and then degrees of closeness and familiarity between people. When two people are paying close attention to each other, check out the others in the group and see who’s observing. Human dynamics are amazing, but so much that you might learn is subconscious interplay. In fiction, one needs to somehow convey all of that with only a few words, for it to work, and one quick way in, is establishing a private language between two characters. Do that and you convey long familiarity, privately shared experiences, and a whole host of other details.