This document provides an overview of speech acts, including their definition, historical context, research methodologies used to study them, and empirical studies on speech act sets such as apologies, refusals, compliments, complaints, and requests. Speech acts are functional units of communication that depend on social and cultural factors. Researchers have studied their production and perception using methods like discourse completion tasks, role plays, and interviews. Studies have found differences between native and non-native speakers in selecting appropriate speech act strategies and forms.