Language is implicated in daily lives, and there are a large and open-ended number of activities (Cook, 2003), which involve language theories (Alkhaldi, 2011). This research analyses the language theories which are involved in the activities of Jordanian language materials. The researchers have chosen a sample from language materials used to teach English at Jordanian public high schools since 2015. An analysis checklist has been adapted and used, focusing on the analysis of language theories. The findings show that the students’ role is responsive rather than proactive. The dominant source of content is the materials, and the teachers’ role is overlooked in providing useful language content. Furthermore, the mental operations have not been taken to the deepest level to promote students’ creative and critical thinking skills. The findings also reveal that the materials have a sentence-based content, that is, the content provided as input to learners and content expected as output from the learners comprise individual words, phrases and sentences, and there are few opportunities for extended written and oral discourse. Consequently, it is recommended that teachers, researchers and materials developers should take into consideration such challenging findings to bridge the gap between theory and practice and to develop language materials effectively. In other words, the materials should continuously be analysed, evaluated, and developed in a systematic and rigorous way to have insights into the materials and the process of analysis for professional development purposes, and to help students improve their language learning process.