If I Keep Listening...Will I be Able to Understand?

The other day, Paul just wrote about his experience of using TPR (Total Physical Response) approach in an EFL classrooms. I belive the TPR approach was based on Krashen's comprehensible input, which suggests that all language teachers need to do is to provide authentic and sufficient input for our students; when learners are ready, they can start to produce language output.

As soon as the hypothesis was proposed, some researchers was ready to attack. Yesterday I happend to read some research findings related to comprehension-based ESL/EFL classrooms in Lightbown & Spada's (1999) article-Second Language Learning in The Classroom. I couldn't find it online..do want to recommend it though it's a little too long.

So, the conclusion of those research findings is ' although comprehensible input seem contribute positive effect on language learning, it is considered to be insufficient to help learners develop their language ability to advanced levels.
A possible explanation is 'when learners are exposed to language input, they are more likely to acquire forms that frequently appear in the input' That is, for some less-frequent words or phrases, unless learners pay more attention on them, they are not likely to be acquired.

Go back to the TPR approach, I would like to agree that it is very useful to motivate our students; and it also allows our students to learn some English usages that are frequently used in the classroom (eg. stand up, turn to page 6, class dismissed...and etc.) However, I would still want to emphasize the importance of instruction.

References
Lightbown, P., & Spada, N. (1999). Second Language Learning in The Classroom. How Languages are Learned. (Ch 6).