Introduction: 1. Frequency of experience; 2. A cognitive perspective on language; 3. What this book is not about; 4. What this book is about; Part I: 5. Counting occurrences: how frequency made its way into the study of language; 5.1. The frequency wars: the role of frequency in nativist and nurturist frameworks; 5.2. Lexical statistics and word (frequency) lists; 5.3. Word lists in psycholinguistics: the discovery of the (word) frequency effect; 5.4. Word frequency distributions and the beginning of quantitative linguistics; 5.5. Summary and outlook; 6. Measuring exposure: frequency as s linguistic game-changer; 6.1 Frequency and usage-based theories of language; 6.2. Frequency measures that have played an important role in the development of usage-based theories of language; 6.3. Summary and outlook; 7. More than frequencies: towards a probabilistic view on language; 7.1. Constructing a grammar from the ground up; 7.2. probabilistic grammar; 7.3. Probabilities link linguistics to information theory; 7.4. Summary and outlook; Part II: 8. Committing experiences to memory; 8.1. What is memory?; 8.2. The physiology or neurobiology of memory; 8.3. Memory systems, memory processes and neural mechanisms of memory storage; 8.4. Behavioural diagnostics of memory for language; 8.5. Summary and outlook; 9. Entrenching linguistic structures; 9.1. Entrenchment in the mind, or in society?; 9.2. Three types of entrenchment; 9.3. How are repeated experiences recorded?; 9.4. Frequently asked questions; 9.5. Summary and outlook; Part III: 10. The brain's attention-orienting mechanisms; 10.1. Grasping the phenomenon: what is attention and what does it do?; 10.2. Ways of deploying attention; 10.3. Attention and memory: encoding and retrieving information; 10.4. Summary and outlook; 11. Salience: capturing attention in and through language; 11.1. Capturing attention in language: linguistics versus psychology; 11.2. Attention and salience; 11.3. Conclusions and outlook; Part IV: 12. Predicting: using past experience to guide future action; 12.1. Predicting from stored memories; 12.2. Memoryless prediction: Bayesian predictive coding frameworks; 12.3. What does predictive processing mean for language cognition? 12.4. Conclusions and outlook; 13. Learning: navigating frequency, recency, context and contingency; 13.1. Background: learning theory; 13.2 Applications to linguistics; 13.3. Conclusions: the place of frequency in a learning theoretic approach to language; 14. Conclusions; 14.1. Why do frequencies of occurrence play an important role in usage-based linguistics?; 14.2 How can frequency be used to explain the construction of a grammar from the ground up?; 14.3. Memory, attention and learning in the emergence of grammar; 14.4. Looking forward: what lessons can we learn?; 14.5. By way of conclusion.