This study analyzes the type of responses that children between 4 and 5 years of age give to different tasks: conservation, classification and tasks of the theory of mind (ToM). Types of responses were observed with the Observation of Cognitive and Meta-cognitive Skills Inventory, which identifies: attention, receptive and expressive language, planning processes, and meta-cognitive processes. Significant differences were found according to the variable age in: (a) the use of attentional strategies in performance of ToM tasks, (b) the use of receptive and expressive language in the performance of all tasks, (c) the use of planning processes in the performance of conservation tasks; and (d) the use of meta-cognitive processes to solve ToM tasks.