Applied linguistics is an interdisciplinary field that identifies and offers solutions to real-world language problems. It utilizes linguistic research to improve practical tasks involving language. Applied linguistics is concerned with language teaching and learning, testing, psycholinguistics, sociolinguistics, discourse analysis, computational linguistics, and translation studies. Over the 20th century, language teaching methods evolved from the grammar translation method to the direct method, audiolingual method, and finally communicative language teaching in response to developments in linguistics, psychology and changes in views about language learning.