Teacher Should Know," which serves as a concise glossary for commonly used idioms and slang in the United Kingdom. This guide lists twenty distinct phrases such as "Fancy," "Knackered," and "Sorted," each accompanied by a brief definition of its meaning and usage. The purpose of this resource is to educate English language instructors about specific vocabulary that students might encounter in the UK. Overall, it functions as a quick reference tool for understanding regional language variations.