This document discusses the application of semantic field theory to English vocabulary learning. It defines a semantic field as the relationship between words based on their meanings. Semantic fields include hyponymy, antonymy, and synonymy. Hyponymy refers to a specific instance of a more general word, like how "rose" is a hyponym of "flower." Antonymy forms relationships between words with opposite meanings. Synonymy connects words with similar meanings. The document argues that understanding semantic fields can improve vocabulary learning and language acquisition. It concludes that the size of one's vocabulary affects linguistic competence, so semantic field theory provides useful insights for teaching English vocabulary.