In relation to language learning, memory is a very important feature of the human brain. Mnemonic processes are fundamental prerequisites for encoding, storing and retrieving new vocabulary and language structures, and in this process of language acquisition new semantic structures are created that are relevant both on a cultural and personal level. An examination of the functions of short-term memory and long-term memory, as well as of the major theories of memory loss and its specific role in the retention and retrieval of information, and specifically, of the role of memory in relation to stress, to a playful language learning approach and to global and contextual language learning, leads to the introduction of the most effective teaching methods for vocabulary retention and the most common mnemonics techniques.