“exposure to language input provides learners with positive evidence (information about what is grammatical in the second language), it fails to give them negative evidence (information about what is not grammatical). Positive evidence is not enough to permit learners to notice the absence in the target language of elements that are present in their interlanguage (and their first language). Thus, more explicit information about what is not grammatical in the second language may be necessary for learners’ continued development. This is discussed in more detail in the section ‘Get it right in the end’.”