
In addition, titles fall into one of three sub-categories: "Contemporary", "Classics" or "Originals". "Penguin Readers" are graded at seven levels of difficulty, from "Easystarts" with a 200-word vocabulary, to Level 6 (Advanced) with a 3000-word vocabulary. Many titles in the series also provide access to the pre-20th century literature strands of the National Curriculum English Orders.

Originally designed for teaching English as a foreign language, the series' combination of high interest level and low reading age makes it suitable for both English-speaking teenagers with limited reading skills and students of English as a second language. Is she dead or not? And is she the lady in the lake? "Penguin Readers" is a series of simplified novels, film novelizations and original titles that introduce students at all levels to the pleasures of reading in English. Private detective Philip Marlowe is looking for the missing wife of Derace Kingsley.
