Some people having their own way to show to the people they love that's they really care and want that person to be with them, but some people doing it piece by piece because they can't show it straight away because its might be the having really bad experience on the past which they don't want to feel it again.
So, for you all who having a relationship or some special connection with these people i recommend you to always be patient and trust them and you also can show them that they do not need to worry about anything because you also love them and want them in your life and might be with this way, they going to more open and show you how deep they really love and like you.
But like i said its need a time is not going to happens straight away so just be patient and always show them that you love them for who they are you don't care at all even they just show you that they care about you with by little piece, because you are really love them and they are just amazing the way they are.