With the outbreak of World War II armies needed to become orally proficient in the languages of their allies and enemies as quickly as possible. This teaching technique was initially called the Army Method, and was the first to be based on linguistic theory and behavioral psychology. The Audio-lingual Method was widely used in the 1950s and 1960s, and the emphasis was not on the understanding of words, but rather on the acquisition of structures and patterns in common everyday dialogue. These patterns are elicited, repeated and tested until the responses given by the student in the foreign language are automatic. The Audio-lingual Method is still in use today, though normally as a part of individual lessons rather than as the foundation of the course. These types of lessons can be popular as they are relatively simple, from the teacher’s point of view, and the learner always knows what to expect.