Ellis (2008) discusses ten principles that should guide teachers to promote “instructed second language acquisition”. He also provides teaching suggestions for each of the ten principles. This is one of his suggestions: “Ensure that learners are developmentally ready to acquire a specific target feature. However, this is probably impractical as teachers have no easy way of determining what individual students know. It would necessitate a highly individualized approach to cater to differences in developmental level among the students” (p. 3). This suggestion is given to put principle __________ into practice