Both young children and adults are excellent word learners. Behavioral studies indicate that there are differences in how the two groups accomplish this task, suggesting that the mechanism in which words are learned changes with age. One component of word learning is the associative linking of a label to an object. In the current adaptive artificial language learning paradigm, we examined this process. Participants between the ages of 8 and 25 years learned the association between multi-featured geometric figures (e.g., a red square that bounces) and multi-syllable pseudowords (e.g., MO-DA-SI). Each syllable of the pseudoword is determined by one specific feature of the shape (i.e., MO = color, DA = shape, SI = manner of motion). A previous version of this task for adults was designed to measure knowledge accumulation by fitting a state-space model on a trial-by-trial basis (Berkers et al., 2018). With the current version of the task, modified to be suitable for both children and adults, we ask (1) if the process of language knowledge accumulation changes as a function of age, and (2) if this measure of language knowledge accumulation can be related to an individual’s vocabulary. We expect that age plays a role in language knowledge accumulation and furthermore predict that this measure is related to vocabulary. The results from this study will provide new answers to the question of how the word learning mechanism changes with age.