This document discusses how to develop the four language skills of listening, speaking, reading, and writing. It begins by defining language as a system of communication using letters, words, and sentences. Language is then described as a skill acquired through practice rather than just knowledge. Each of the four skills are then defined: listening is receiving language through ears, speaking is delivering language through the mouth, reading is getting meaning from written symbols, and writing is communicating thoughts through written symbols. Specific techniques for developing each skill are provided, such as audio lectures for listening, role plays for speaking, flipped learning for reading, and story writing for developing writing abilities. The document concludes that these four skills are important for language teaching and communication.