Table 1.

An example of verbal operants that are formally the same, but have different antecedent controlling variables and are maintained by different consequences

Verbal operant	Antecedent	Response	Consequence
Echoic	Another person says “Train”	“Train”	Nonspecific reinforcement/praise
Mand	Providing a track with no traina	“Train”	Access to a train
Tact	A picture scene with a train	“Train”	Nonspecific reinforcement/praise
Intraverbal	“What goes choo choo?”	“Train”	Nonspecific reinforcement/praise

^aThere must be a motivating operation in place for the train set (i.e.., the child must “want” to play with the train set)