Sometimes I have honestly not known what to say but I can also see that my therapist also wasn't sure of exactly what I needed. Part of therapy is learning to how to ask for what you need from friends, family, partners, co-workers, and other people who come into contact with. It can be really, really hard. Right now I am struggling with that very issue.

I think it is always ok to say you don't know. Sometimes what I find helpful is to state what I wish could happen. That can be different than what someone can specifically do. For example, once I said I what I really wanted was to experience a mother who wasn't critical because I didn't know what that was like. That isn't something my therapist could specifically do for me but it did help move me forward.