If teachers have an awareness of the likely difficulty of a task, based on Cummins' model, they can judge its appropriateness for the non-native speakers in their classes and in this way avoid much frustration. This does not mean, however, that ESL students should be fed a diet of cognitively-undemanding tasks. It may be beneficial to use such activities in the student's early days at school, in order to build confidence, or as a lead in to a more challenging activity. However, teachers should switch soon to tasks that engage the students' brains, making these tasks accessible by providing visual or other support. Once students are comfortable with these kinds of activities, they can be gradually exposed to tasks that are both cognitively-demanding and context-reduced.
Additive/subtractive bilingualism
Cummins draws the distinction between additive bilingualism in which the first language continues to be developed and the first culture to be valued while the second language is added; and subtractive bilingualism in which the second language is added at the expense of the first language and culture, which diminish as a consequence. Cummins (1994) quotes research which suggests students working in an additive bilingual environment succeed to a greater extent than those whose first language and culture are devalued by their schools and by the wider society.