Language proficiency largely relies on implicit knowledge, which is unconscious and operates independently of voluntary control. Implicit learning is a process of incidental learning which results in the acquisition of implicit knowledge. We know that adult learners can acquire knowledge of novel L2 linguistic rules through implicit learning, as evidenced by their performance on receptive tasks. However, it is unclear whether implicit learning processes can also support the development of L2 production skills. The central question of this dissertation was whether it would be possible for learners to acquire implicit knowledge of a new rule through implicit learning and use it directly in spoken production. Our second question concerns the relationship between production and comprehension: we asked whether implicit knowledge acquired through a production task would also lead to improved performance in comprehension. To address these questions, we trained participants on a semiartificial language based on a rule naturally found in Czech: specifically, the usage rule for a pair of spatial prepositions (v and na) which alternate depending on the distinction between open and enclosed spaces. Training was carried out using a novel methodology based on elicited oral imitation, which was also used to test productive knowledge. Participants were also tested on comprehension, using both reaction time and recognition memory paradigms. Our findings suggest that it is possible to acquire implicit productive knowledge through a production-based task, and to generalise it to new instances in spoken production. The results of our experiments also show that learning outcomes were sensitive to the specific procedure used to train participants, which appeared to interact with individual differences in working memory. Finally, we found limited evidence that implicit knowledge acquired through production could be transferred to comprehension, supporting a skill-specific account of implicit knowledge.