Willing to accommodate the task in their own classroom, language teachers will naturally want to fall back on the whole TBLT approach, in search of its defining characteristics and guidelines. Yet, the concept of task-based (language learning and teaching)—similarly the concept of task—can be elusive. This is why a popular way of defining task-based instruction is through a set of criteria or principles. The sets that are a popular point of reference in the field have been proposed by Ellis (2009) and Long (2016); Doughty & Long, 2003).