In the past three decades researchers have developed several tasks to measure theory of mind in young children. The current study administered one nonverbal theory of mind task and five verbal theory of mind tasks to a group of three-year-olds and a group of four-year-olds in order to investigate (1) how they perform on a nonverbal transfer task, (2) how the different verbal theory of mind tasks relate to each other, and (3) how the nonverbal transfer task relates to the verbal theory of mind tasks. The nonverbal theory of mind task was modified in a way that controlled children from passing this task by making three-way associations, using the behavioural rule that people look for objects where they last saw them, and using the situational cue of the actor disappearing from the scene to help predict the actor’s behaviour. Results showed that both three- and four-year-olds changed their looking behaviour based on the beliefs of the actor in the nonverbal transfer task. Results furthermore showed that the different verbal theory of mind tasks used in this study were related to each other, and that some of these tasks were more difficult to pass than others. In addition, this study found that the nonverbal transfer task did not correlate to any of the verbal theory of mind tasks. Based on the results of the theory of mind tasks administered, it was argued that three- and four-year-olds have already developed a theory of mind, but fail more difficult theory of mind tasks because of task difficulties not related to theory of mind, most likely information-processing demands.