This chapter deals with syntax rules and grammaticality judgments in the teaching and learning of English as a second and foreign language for linguistically diverse learners. Grammaticality judgment tasks are used in linguistic research to probe speakers’ implicit knowledge about the syntactic rules of language. This chapter discusses grammaticality judgment tasks in educational contexts and proposes a method for teaching syntactic rules of English based on the grammaticality judgments of second and foreign language learners of English. The chapter also attempts to raise grammatical consciousness for teaching of English as a second or foreign language as well as illustrating how various media can be used to design and present grammaticality judgment tasks to support language learning and learner engagement, participation, and motivation.