This core is theoretically enough for everyday life. However, Ogden prescribed that any student should learn an additional 150-word list for everyday work in some particular field, by adding a list of 100 words particularly useful in a general field (e.g., science, verse, business, etc.), along with a 50-word list from a more specialised subset of that general field, to make a basic 1000-word vocabulary for everyday work and life.