Language proficiency refers to an individual's ability to proficiently understand, speak, read, and write in a particular language. Research in this area typically focuses on examining the various factors that influence language proficiency, such as age of acquisition, exposure to the language, cognitive abilities, and motivation. Researchers may also investigate different methods and approaches to language learning and teaching that can enhance language proficiency. The ultimate goal of this research is to help individuals effectively communicate and interact in a second or foreign language.