This plenary speech provides an overview of applications of corpus research in several core areas of applied linguistics, including second language acquisition and language assessment. It does this by showcasing a number of recent studies carried out by or with involvement of the author. These studies all focus on phraseological aspects of language and demonstrate the importance of studying its patterned nature. The studies also illustrate how corpora and corpus-analytic techniques can allow us as applied linguists to contribute to solving problems in other disciplines (such as legal scholarship or music theory) and hope to thereby encourage more interdisciplinary research collaborations between corpus linguists and scholars from other fields.