The article investigates the acquisition of the metaphor TIME IS A MOVING ENTITY in English and Turkish. A warm-up task, a story comprehension task and a an open-ended interview were conducted on 40 monolingual English-speaking (ages 4, 5), 60 monolingual Turkish-speaking children (ages 3, 4, 5) and a control group of 20 adults for each language. The results revealed a three-stage developmental pattern: at age 3 children were unable to understand the metaphor, at age 4 they could comprehend it with a supporting story context and by age 5 they were able to think about it at a conceptual level, as evidenced by their ability to reason about the different linguistic realizations of the mapping. Children were also able to differentiate between conventional and unconventional linguistic instantiations of the metaphor by age 5. These results hold true for English and Turkish and reveal an earlier onset of metaphorical thinking than what had been reported in previous works. This earlier metaphorical reasoning is due to the nature of the source domain, which constitutes a very basic sensorimotor experience for the developing child. The article also reports on earlier work on the lexicalization of the MOTION IN SPACE source domain in adult speakers of English and Turkish, and offers a comparison with children's speech. The results reveal a greater emphasis on the manner of motion in the English verbs used by both children and adults. In spite of this linguistic difference, the conceptual structure of the time as spatial motion metaphor is very similar in English and Turkish and similarly acquired. (Cristina Soriano)