In Italian, when we use informal imperative in positive senteces with a direct, indirect and double object pronouns and also with ci and ne, we use these pronouns and particles as suffix and join them together to the imperative forming a single word. Example: Guardalo!; Diteglielo!; Andiamoci!; Parlane! Parlagliene!
We use the particle ci in many cases. I’ll try to explain you all cases in which italians say ci.