Workplace idioms & slang words - Advance English lesson Idiomatic expressions and slang words have long played an important role in the English language. In fact, the use of idioms and slang words is so widespread that an understanding of these expressions is essential to successful communication, whether in listening, speaking, reading, or writing. The student may learn grammar and, with time, acquire adequate vocabulary, but without a working knowledge of idioms and slang words even the best student's speech will remain awkward and ordinary. In this lesson Niharika brings you some of the commonly used workplace idioms and slang words.