Deconstructing "tomorrow": How children learn the semantics of time

Deictic time words (e.g., “tomorrow,” “yesterday”) refer to time periods relative to the present moment. While children produce these words by age 2-3, they use them incorrectly for several more years. Here, as a case study in abstract word learning, we explored what children know about these words during this delay. Specifically, we probed children’s knowledge of three aspects of meaning: deictic (past/future) status, sequential ordering (e.g., “tomorrow” is after “yesterday”), and remoteness from now. We asked 3to 8year-olds to place these words on a timeline extending from the past (left) to the future (right). Even 4-year-olds could meaningfully represent the words’ deictic status and order, and by 6, the majority displayed adult-like performance. Adult-like knowledge of remoteness, however, emerged independently, after age 7. Thus, even while children use these terms incorrectly, they are gradually constructing a structured semantic domain, including information about the deictic, sequential, and metric relations among terms.