Graded readers or original books?

Start with graded readers if original books give you more than five or six unknown words per page. Move to originals when a graded reader at the top level feels easy. Graded readers let you read a lot of text you understand; originals are the books you actually wanted to read, and the goal.

By the Readlang Mobile team (an independent app, not affiliated with readlang.com). Updated .

What graded readers are

Graded readers are books written or adapted for language learners, with the plot, vocabulary and grammar controlled level by level. The Extensive Reading Foundation also calls them language learner literature. Each level allows a fixed number of headwords, the base words a writer may use, so a reader at that level meets few words outside the list. There is fiction and non-fiction, and many of the novels are retellings of classics.

Two of the best-known English series, with the publishers’ own headword counts and CEFR levels:

Levels of Oxford Bookworms and Penguin Readers, as published by Oxford University Press and Penguin Random House.
Oxford BookwormsHeadwordsCEFR Average wordsPenguin ReadersHeadwords CEFRStory length
Starter250A11,375 Starter350Pre-A1400–600
Stage 1400A1–A25,200 Level 1550A11,000–1,600
Stage 2700A2–B16,500 Level 2700A1+3,000–5,000
Stage 31,000B110,000 Level 31,000A27,000–10,000
Stage 41,400B1–B216,000 Level 41,200A2+11,000–14,000
Stage 51,800B223,000 Level 51,600B115,000–18,000
Stage 62,500B2–C130,000 Level 62,000B1+18,000–22,000
Level 72,500B222,000–26,000

Two cautions. Headwords are not the same as the words you know: one headword covers several forms, and publishers count them differently. And the CEFR labels are the publishers’ own; the same headword count sits at B1 in one series and A2 in the other. Compare the headword numbers, not the level names. The Extensive Reading Foundation says the same and publishes its own scale based on headwords only.

The reason graded readers work is simple arithmetic. Paul Nation counted the words in an Oxford Bookworms retelling of The Picture of Dorian Gray at 1,000 headwords: a reader who knows the 3,000 most frequent English word families, plus the characters’ names, knows 98.86% of its words. For an ordinary novel, 98% takes 8,000 to 9,000 word families.

Graded readers and originals side by side

How the two kinds of books differ for a learner.
Graded readersOriginal books
VocabularyLimited to a fixed list for each level, so the share of known words stays highWhatever the author needed; the share of unknown words depends on the book, not on you
GrammarControlled by level: simple tenses first, complex sentences laterEverything at once
LengthShort at low levels, longer at high levelsAnything from a short story to a thousand pages
RepetitionThe same words come back often, which helps you learn themRare words may appear once and never again
ChoiceA wide range in English, far fewer titles in most other languages; many are retold classicsEverything ever written
LanguageSimplified, sometimes flat; retellings lose the author’s styleReal, with the author’s voice, humour and culture
CostMostly paid; libraries and schools often have setsPublic-domain classics are free; modern books are paid

What research says about reading a lot of easy text

Reading a lot helps, moderately. Two meta-analyses pooled dozens of studies of extensive reading, where learners read many easy books of their own choice. Takayuki Nakanishi (2015) combined 34 studies and found a medium effect on reading proficiency compared with learners who did not read extensively. Eun-Young Jeon and Richard Day (2016) combined 49 studies and found a similar effect, larger for adults than for children and teenagers. A 2025 review reached the same conclusion across comprehension, vocabulary, fluency and motivation: consistent, small to medium gains.

One book teaches few words for good. Rob Waring and Misako Takaki (2003) had 15 learners read a 400-headword graded reader containing 25 invented words. Right after reading, the learners could translate on average 4.6 of the 25; three months later, 0.9. After three months, none of the words met fewer than eight times was remembered.

Words that come back are learned. Ana Pellicer-Sánchez and Norbert Schmitt (2010) had 20 advanced learners read an unabridged novel, Things Fall Apart, which uses Igbo words new to every reader. Words met more than ten times were recognised 84% of the time; words met once, 29%. Other studies agree that about ten encounters produce solid gains, though full knowledge of a word takes more.

Put together: the benefit comes from volume, and volume is only possible in books you can read without constant stopping. That is the case for graded readers, and also the case for any original book that passes the one-page test.

Between the two

The jump from graded readers to originals does not have to be one step. Some books sit in between:

When to switch

Switching does not have to be final. Many learners read an original book slowly and a graded reader quickly at the same time: one for challenge, one for volume.

Sources

  1. Extensive Reading Foundation (2011). The Extensive Reading Foundation’s Guide to Extensive Reading. erfoundation.org/guide/ERF_Guide.pdf
  2. Extensive Reading Foundation. ERF Graded Reader Scale. erfoundation.org
  3. Oxford University Press. Oxford Bookworms Library: levels and word counts, checked 28 September 2026. oup.es, oupjapan.co.jp
  4. Penguin Random House (2019). Penguin Readers Handbook. penguinreaders.co.uk
  5. Nation, I. S. P. (2006). How large a vocabulary is needed for reading and listening? The Canadian Modern Language Review, 63(1), 59–82. doi.org/10.3138/cmlr.63.1.59
  6. Nakanishi, T. (2015). A meta-analysis of extensive reading research. TESOL Quarterly, 49(1), 6–37. doi.org/10.1002/tesq.157
  7. Jeon, E.-Y. and Day, R. R. (2016). The effectiveness of ER on reading proficiency: A meta-analysis. Reading in a Foreign Language, 28(2), 246–265. Full text (ERIC)
  8. Sangers, N., van der Sande, L., Welie, C., Dobber, M. and van Steensel, R. (2025). Learning a language through reading: A meta-analysis of studies on the effects of extensive reading on second and foreign language learning. Educational Psychology Review, 37(4), article 96. doi.org/10.1007/s10648-025-10068-6
  9. Waring, R. and Takaki, M. (2003). At what rate do learners learn and retain new vocabulary from reading a graded reader? Reading in a Foreign Language, 15(2), 130–163. doi.org/10.64152/10125/66776
  10. Pellicer-Sánchez, A. and Schmitt, N. (2010). Incidental vocabulary acquisition from an authentic novel: Do Things Fall Apart? Reading in a Foreign Language, 22(1), 31–55. Full text (ERIC)
  11. Webb, S. (2007). The effects of repetition on vocabulary knowledge. Applied Linguistics, 28(1), 46–65. doi.org/10.1093/applin/aml048

Next: Reading with a dictionary.