The 21st century skills have been recognized as this century's sensation in the educational field and have drawn much attention since the 80s of the last century. The implementation of those skills has been included in most school subjects in many countries around the world and there has been numerous research done in that matter. A short review of literature proved that there has been little discussion about teaching those skills in a second language (esp. English) teaching context. That is one of the reasons for conducting this research aimed at discovering the possibility and impact of implementing 21st century skills, namely critical thinking and problem solving in ELT classes. The main purpose of this research is to create and conduct lessons that enhance learners' critical thinking and problem solving skills in an ELT class environment, and collect participants' and researcher's feedback to discover whether English classes could be conducted in light of the skills mentionedabove and whether those skills could be a carrier or a barrier of the target language learning.