The following text is part of the article Principles of Instructed Second Language Acquisition of professor Rod Ellis who formulated a set of general principles for instructed language acquisition. Principle 8 will be used for the next question.

TEXT - Principle 8: The opportunity to interact in the second language is central to developing second
language proficiency
While it is useful to consider the relative contributions of input and output to acquisition, it is also important to acknowledge that both occur in oral interaction and that this plays a central role in second language acquisition. As Hatch (1978) famously put it, “One learns how to do conversation, one learns how to interact verbally, and out of the interaction syntactic structures are developed” (p. 404). Thus, interaction is not just a means of automatizing what the learners already know but also about helping them to acquire new language. According to the Interaction Hypothesis (Long, 1996), interaction fosters acquisition when a communication problem arises and learners are engaged in negotiating for meaning. The interactional modifications that arise help to make input comprehensible, provide corrective feedback, and push learners to modify their own output by repairing their own errors. According to sociocultural theory, interaction serves as a form of mediation, enabling learners to construct new forms and perform new functions collaboratively (Lantolf, 2000). According to this view, learning is first evident on the social plane and only later on the psychological plane. In both theories, social interaction is viewed as a primary source of learning. Figure 5 identifies five key requirements for interaction to create an acquisition-rich classroom. Creating the right kind of interaction for acquisition constitutes a major challenge for teachers. One solution is to incorporate small group work into a lesson. When students interact among themselves, acquisition-rich discourse is more likely to ensue. However, there are also dangers in group work (e.g., excessive use of the native language in monolingual groups) that teachers need to guard against.

To create an acquisition-rich classroom, teachers need to:
- create contexts of language use where students have a reason to attend to language,
- allow students to initiate topics and to control topic development,
- provide opportunities for learners to use the language to express their own personal meanings,
- help students to participate in language-related activities that are beyond their current level of proficiency,
- and offer a full range of contexts that provide opportunities for students to engage in a full performance in the language.
(Ellis, 1999; Johnson 1995).