Using the appropriate level of formality when speaking is critical to social and business success. Learning the differences between formal and informal speech will help you speak appropriately, whatever the setting.
Two main vocabulary differences exists between formal and informal speech. Those using formal language tend to use longer words such as “demonstrate” rather than the more informal “show” as well as the more formal word “endeavor” rather than “try.” Formal speech contains fewer phrasal verbs, with informal speakers choosing, for instance, “sit” rather than “sit down.”
Three important grammatical differences exists between formal and informal speech. Formal speech generally consists of complete, grammatically correct sentences. When speaking informally however, speakers of English often omit noncritical words. For example, informal speakers might say, “Where you going?” rather than the formal, “Where are you going?” Speakers use the passive voice more frequently when speaking formally; they might say, for example, “I have been given some information by John,” rather than the active and informal, “John gave me information.” Additionally, English speakers use contractions when speaking informally, such as, “They're coming at six,” rather than the more formal, “They are coming at six.”