This document discusses semantics, which is the study of meanings of words, phrases, and sentences. It describes conceptual meaning as the basic components of a word's meaning, and associative meaning as additional connotations. Sentences can be syntactically correct but semantically odd. Words fulfill roles like agent, theme, instrument, location, source, and goal within a sentence. Relationships between words like antonyms, hyponyms, homophones, and homonyms are explained. Frequently occurring word pairs are known as collocations.