This answer key accompanies the first volume of 4000 Essential English Words. The supplied pages cover Units 1–24, presenting numbered solutions under the same exercise and reading comprehension headings used throughout the material. Its compact arrangement makes it possible to locate a unit, identify a particular exercise, and compare a completed response with the listed answer. The vocabulary sections include multiple-choice letters, individual words, and paired answers. Examples range from adventure, approach, and secret to technology, personality, pressure, and friendship. Some exercises distinguish related words or contrasting meanings, including whole and hole, fix and damage, and island and ocean. Other sections supply completed forms such as expected, avoided, gathered, and hurried, allowing learners to check the wording required by individual tasks. Each unit also includes reading comprehension answers, usually four letter choices followed by a short written response. These responses recall concrete details from the accompanying readings: a lion seeing its reflection, children entering a laboratory, a traveler viewing Mars, starfish returning to the water, and a rabbit noticing a turtle near the finish line. Later examples concern helping hospital patients, reporting a thief, learning boat safety, and recognizing friendship. Used alongside the corresponding exercises and readings, the document provides a straightforward reference for checking completed work. It supplies answers rather than extended explanations, vocabulary definitions, or the complete reading passages.