To find out if children could make functions before age 4, 73 children aged 1 to 4 were encouraged to imitate the use of a lever to make a beanbag fly up. Functions are mental relationships that preoperational children can make between 2 things at a time in a unidirectional way (Piaget, Grize, Szeminska, & Bang, 1968/1977). The child's construction of the following 3 functions was hypothesized and confirmed: (a) As a function of being pushed down, the up end of the board (the lever) goes down; (b) as a function of this descent, the down end of the board goes up; and (c) as a function of this ascent of the board, the beanbag flies up. Three developmental levels were found, and educational implications are discussed.