1.3. Principle II: Engage in extensive extemporaneous speaking.
In my own experience, Krashen's input hypothesis has been enormously helpful. Yet it appears that few scholars agree with the hypothesis in its entirety. That is because Krashen doesn't just claim that comprehensible input is the most important factor in second language acquisition. He claims that it is the only factor!
- 1.3.1 Comprehensible input is not enough
- 1.3.2 You can't speak well unless you can speak poorly.
Merrill Swain (1985) examined the French ability of children who had been in a school immersion program for seven years. These children, who were from English speaking homes, had received all of their elementary education in French. Yet after seven years of receiving truly massive comprehensible input in French, they still did not control the French language like native French speaking children did. Why not? Probably there were a number of problems, but an obvious one was that the students didn't have much opportunity to speak the language. They mainly listened to the teacher. When they spoke to one another informally, they used English. When they spoke to the teacher they used French. But then, how much class time is devoted to any one student speaking to the teacher? And the only children they ever heard speaking French were their class-mates, non-native speakers like themselves, and that only happened when their classmates were addressing the teacher. You certainly couldn't say that the children used French in a very rich variety of life situations, or that they used French for a very wide variety of communication purposes. It appears that, since they didn't speak French very much, their speaking ability did not develop as well as we might have hoped. Even their ability to understand French appears to have suffered from the fact that they did not speak it very much. That's not to say they didn't learn French quite fluently. But Swain conjectures that they might have done better if they had been speaking French extensively, in addition to all their years of listening to comprehensible input.
You may know children of immigrant parents who can understand their parents' language quite well, but cannot speak it at all. Nancy Dorian (1981) noticed that although she had learned to speak Gaelic in the course of her research, young people with Gaelic speaking parents, although they could not speak the language at all, could often understand it better than she could. They had grown up with massive comprehensible input, and had developed a high degree of comprehension ability, but little or no speaking ability.
So it appears that massive comprehensible input can result in people having the ability to understand a language without necessarily being able to speak it well, or even to speak it at all. It appears that in order to learn to speak, you have to put a certain amount of effort into speaking. Somehow, I don't find that surprising.
You might ask whether it is possible to learn to speak without receiving much comprehensible input. Some linguists have told me that their speaking ability exceeded their comprehension ability, at least for a long time. Recently one told me that he could plan and execute a very complicated sentence in a certain African language, but that if he heard the same sentence in natural speech he would have difficulty understanding it. My experience in learning Blackfoot was similar. For a long time my speaking ability exceeded my comprehension ability. That is not a very good way to learn a language, for a number of reasons. For one thing, if you can say a lot more than you can understand, people will misjudge your general level of ability in the language, and speak to you in such a way that much of what they say will go over your head. This can make conversational experiences embarrassing and stressful, and discourage you from spending a lot of time conversing with people. So you want to keep the horse of comprehension ahead of the cart of speaking, while bearing in mind that comprehensible input in and of itself is not enough