Vocabulary learning occurs throughout the lifespan, often implicitly. For foreign language learners, this is particularly challenging as they must acquire a large number of new words with little exposure. In the present study, we explore the effects of contextual diversity-namely, the number of texts a word appears in-on native and foreign language word learning. Participants read several texts that had novel pseudowords replacing high-frequency words. The total number of encounters with the novel words was held constant, but they appeared in 1, 2, 4, or 8 texts. In addition, some participants read the texts in Spanish (their native language) and others in English (their foreign language). We found that increasing contextual diversity improved recall and recognition of the word, as well as the ability to match the word with its meaning while keeping comprehension unimpaired. Using a foreign language only affected performance in the matching task, where participants had to quickly identify the meaning of the word. Results are discussed in the greater context of the word learning and foreign language literature as well as their importance as a teaching tool. Vocabulary learning is an essential aspect of language that continues throughout the lifespan. To a large extent, the vocabulary we incorporate comes from incidental learning during reading 1,2 rather than explicit effort. This becomes particularly relevant when learning a new language, where a large amount of vocabulary must be acquired very quickly and partially without supervision. Following this reasoning, several studies have shown that it is possible to learn vocabulary implicitly through reading in our foreign language 3-7. In addition, we know that people incorporate new lexical forms with as little as one exposure in their native language and as little as two exposures in their foreign language 4 , but that learning improves with exposure to multiple instances of the word 8. Implicit word learning in context differs somewhat between one's native and foreign languages. In particular, reading times for new words in our native language decrease significantly after the first exposure-suggesting some level of incorporation of the lexical item-whereas for the foreign language this happens only after two to four exposures 4. This might relate to the fact that it is more difficult to extract the meaning of words from context in a foreign language. This is in part because these skills seem to be affected by knowledge of the language and experience in that particular task 9,10. Although the number of times people encounter a word affects how well they learn and remember it 5,8 , there is not much literature on how spreading these encounters across passages affects learning. One of the ways in which this spread is quantified is through contextual diversity-namely, the number of texts in which a word appears in a database 11,12. This variable can be used to describe the influence of context beyond the mere number of occurrences or the frequency with which we encou...