--- - |2+ Abstract We investigated the effect of age and directive words on children's ability to semantically integrate speech and iconic gesture. The participants were 132 children aged 4 to 6 years old. In the experiment, we presented messages of actions in 3 conditions (Verbal‐only, Gesture‐only, and Verbal‐Gesture) in a serial manner to assess multimodal gain as the ability and had participants select 1 answer corresponding to each message from among 4 options. Participants were divided according to whether the messages of various speech and gestures used directive words or not (e.g., “one is throwing like this” vs. “one is throwing”). The results showed that participants in the directive‐word‐present condition were more likely to select the correct answer than the participants in the directive‐word‐absent condition were. Our results suggest that directive words promote young children's ability to semantically integrate speech and gesture, and therefore are useful for promoting communication. Highlights We examined whether the presence or absence of directive words influence young children's comprehension of speech and iconic gestures to communicate actions. One hundred thirty‐two 4 to 6‐year‐old children were presented with eight messages using speech and gesture either with or without including directive words. The results showed that participants in the directive‐word‐present condition were more likely to select the correct answer than the participants in the directive‐word‐absent condition were. We concluded directive words promote young children's ability to semantically integrate speech and gesture, and therefore are useful for promoting communication. - Infant and Child Development, Volume 27, Issue 5, September/October 2018.