Pragmatics has grown into an established discipline over the past 30 years. It is concerned with the relationship between language forms, meanings, and users. Pragmatics studies how linguistic expressions are used and interpreted in different contexts. A key aspect of pragmatics is assigning reference and sense to words based on inferences from the context and speaker's intended meaning. Social factors also influence language use, such as politeness principles and conventions for conversation turns. Context plays a major role in communication by influencing what is said and how it is interpreted. Speech act theory and insights from politeness theory have impacted foreign language teaching.