This was written by linguist Stephen Krashen, professor emeritus at the University of Southern California, is an educational researcher and activist. He has written hundreds of articles and books in the fields of second language acquisition, bilingual education, and reading.

By Stephen Krashen

In a recent issue of the Washington Post Express, Andrew Eil, a staffer who works at the U.S. State Department on international climate change, recommends that foreign language students start with “boot camp:” Study grammar very hard, drill vocabulary every day, and force yourself to talk. This regimen, he claims, put him in a position to develop high levels of competence in several languages; he now speaks Russian and French fluently and can converse in Mandarin and Kazakh.

Most of us who have taken foreign languages classes that emphasize heavy grammar instruction and memorizing vocabulary would disagree with his recommendations, and so does the research.

The results of studies done over the last few decades by a wide variety of researchers and published in scientific journals support this view: We do not master languages by hard study and memorization, or by producing it. Rather, we acquire language when we understand what people tell us and what we read, when we get “comprehensible input.” As we get comprehensible input through listening and reading, we acquire (or “absorb”) the grammar and vocabulary of the second language.

Studies show repeatedly that intensive grammar study and memorizing vocabulary are of limited value: Students in classes that provide lots of comprehensible input (e.g. methods such as TPRS) consistently do better than students in traditional grammar-based classes on tests that involve real communication and do just as well, and often better, on grammar tests. These students have acquired the grammar and vocabulary of the language naturally, and can use what they have acquired in real communicative situations. They are also more likely to continue foreign language study.


The complexity of the grammatical system to be mastered makes it highly unlikely that it can be taught and learned: Linguists have not even described the grammatical system of any language completely and many rules are forbiddingly complex, with numerous exceptions.

Even very complex rules, however, can be acquired (or “absorbed”) through comprehensible input, especially through reading. Here is one of many examples from the research: In one study, English speakers who spoke Spanish as a second language were tested on their ability to use the Spanish subjunctive in conversation. The subjunctive is of interest as it is considered a difficult structure to master. Researchers considered a number of predictors of subjunctive proficiency: amount of formal study of Spanish, amount of formal study of the subjunctive, years of residence in a Spanish-speaking country, and the amount of reading done in Spanish. The only significant predictor was reading in Spanish.


There is a substantial research literature showing that vocabulary knowledge comes largely from comprehensible input, especially reading, in both first and second languages. Many second language speakers acquire enormous vocabularies, and it is highly doubtful that they did it through vocabulary study: In one study, it was reported that speakers of Spanish as a second language who were avid readers in Spanish had larger Spanish vocabularies than native speakers of Spanish who did not do a lot of reading.

Forced speech

Should language students force themselves to talk, as Eil advises? Research informs us that at beginning stages, highly successful second language acquirers often experience a substantial “silent period,” a time when they produce little or no language. The silent period is nearly universal for children acquiring a second language, and there are entire cultures in which second language acquirers are expected to experience a silent period. Also, successful comprehensible-input based methods do not force students to speak.

Forcing language students to speak before they are ready not only makes them extremely uncomfortable but does nothing for language acquisition. Speaking doesn’t cause language acquisition; rather, the ability to speak is the result of comprehensible input.

Comprehensible input at all stages

Andrew Eil has clearly done well in foreign language acquisition, and he acknowledges the value of the experiences he had during his residence in Russia, Kazakhstan, France and China over several years, from the reading he did, the movies he saw, the many conversations he had with others, and other kinds of “informal, friendly interaction.” In other words, he improved thanks to comprehensible input.

Current research strongly suggests that comprehensible input is the way we acquire language at all stages. The kind of “boot camp” Eil recommends is neither necessary nor desirable.



Comprehensible input: Krashen, S. 2003. Explorations in Language Acquisition and Use. Heinemann.

Effectiveness of comprehensible-input based instruction: Krashen, op. cit.; TPRS studies: Varguez, K. 2009. Traditional and TPR Storytelling instrution in beginning high school Spanish classroom. International Journal of Foreign Language Teaching 5 (1): 2-11; Watson, B. 2009. A comparison of TPRS and traditional foreign language instruction at the high school level. International Journal of Foreign Language Teaching 5 (1): 21-24.

Acquisition of Spanish subjunctive: Stokes, J., Krashen, S., and Kartchner, J. 1998. Factors in the acquisition of the present subjunctive in Spanish: The role of reading and study. ITL: Review of Applied Linguistics 121-122:19-25.

Highly successful second language acquirers often experience a substantial “silent period”; Krashen, S. 2000. What does it take to acquire language? ESL Magazine, 3(3), 22-23. (available at http:www.

Cultures in which a silent period is expected: Sorenson, A. 1967. Multilingualism in the northwest Amazon. American Anthropologist, 69 (6), 670-684.

Avid readers of Spanish: Rodrigo, V. 2009. Vocabulary size and reading habit in native and non-native speakers of Spanish. Hispania, 92.3, 580-592.


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