Reading in English: the hard book is study, the easy book is training

You bought the novel you love in the original, or you promised yourself you'd read The Guardian every morning. Ten minutes later you're one page in, with twelve words underlined and a dictionary open on your phone. You call it "reading in English," but you're doing something else.

That hard book is a study session. It teaches you new words, just slowly. What makes you read faster and more fluently is a different activity: reading lots of easy text, almost without stopping. In a year-long study, learners who read only simplified books gained more speed than those who mixed simplified books with original novels, with the amount read held equal. You need both kinds of reading, and almost everyone only does the first.

Easy means one unknown word in fifty#

A text is easy enough to read fluently when you know around 98% of its words. That figure comes from Hu and Nation's 2000 study, which tested texts at 80%, 90%, 95% and 100% known words: at 80% nobody understood adequately, and at 90% or 95% only a minority did. Batia Laufer and Geke Ravenhorst-Kalovski calculated that reaching 98% in authentic texts takes about 8,000 word families.

98% works out to a single unknown word in every 50. If you're underlining a word on every line, you're decoding, not reading.

98% is a rule of thumb, not a precise cliff. The original study rested on only 66 university students in New Zealand, and a 2023 replication with 104 adults in Sri Lanka could not fully reproduce its results. To pick a book, a simpler test from the Extensive Reading Foundation does the job: if you're looking up words often, the book is too hard and you should read something easier. For intermediate readers, Richard Day and Julian Bamford suggest the rule of hand: no more than five difficult words per page.

The easy book trains your speed#

Reading speed grows with the volume of easy text, not with effort per page. Researchers call this extensive reading, which Bamford and Day define as "an approach to language teaching in which learners read a lot of easy material in the new language" (quoted in Jeon and Day). The slow, dictionary-in-hand work on a hard text is its opposite. David Beglar and Alan Hunt followed lower-intermediate Japanese university students for a year, starting from about 97 words per minute. The readers with the biggest fluency gains read an average of 208,607 words, mostly in simplified books up to the 1,600-headword level.

Beglar and Hunt matched 14 pairs of readers on total amount read, and in 12 of them the reader who stuck to simplified books gained more speed. Their conclusion: "simplified texts were significantly more effective for increasing reading rate gains than a mixture of simplified and unsimplified texts."

Stopping at every word breaks exactly what you're training. Day and Bamford advise against dictionary use during extensive reading and cite the vicious circle of the weak reader that Nuttall described: they read slowly, don't enjoy it, read little, and don't understand.

The payoff from reading a lot is real and moderate. A meta-analysis of 49 studies and 5,919 participants found that extensive reading improves comprehension, speed and vocabulary with a small to medium effect, larger in adults than in children and adolescents. The most recent meta-analysis, from 2025, confirms positive effects on writing and speaking too.

Using authentic books for this practice is a planning mistake. Day and Bamford put it bluntly: "This is to confuse the means with the end, and paradoxically to rob students of exactly the material they need to progress to the goal of reading real-world texts."

The hard book teaches words, but slowly#

Reading is not a shortcut to new vocabulary. Rob Waring and Misako Takaki gave 15 intermediate Japanese learners a 400-headword graded reader containing 25 target words. Three months later they remembered the meaning of only 1 of the 25 on average, and none of the words they had met fewer than 8 times.

A word sticks only after many encounters. Ana Pellicer-Sánchez and Norbert Schmitt studied 20 Spanish university students, all with an Erasmus year in England behind them, who read the unadapted novel Things Fall Apart for pleasure. Words met more than 10 times were recognized 84% of the time, but there was little difference between seeing a word once and seeing it four times.

The hard novel does teach, which is why it counts as study. Those Spanish readers picked up real vocabulary from an unadapted book, though the authors warn the gains are unlikely to match explicit teaching. The Extensive Reading Foundation guide reserves texts at 90 to 98% known words for when you want to learn new things, and 98% or more for building speed and fluency.

The easy book does a different job with vocabulary: it locks in what you half-know. Waring and Takaki sum it up: "ultimately learners do not learn a lot of new words from graded reading, but in fact graded reading helps to deepen and consolidate already known language." Repeated encounters are also the idea behind Tabla, which brings back the words you practice right before you'd forget them so you can say them out loud.

How to combine the two#

Read easy and fast almost every day. Day and Bamford put the minimum at a book a week, and Beglar and Hunt propose 200,000 words a year. Graded-reader series such as Oxford Bookworms or Penguin Readers sort their titles by headword level, so start at the level where you pass the rule of hand. Don't stop at every stray word: if the story makes sense, keep going.

Save the hard book for short study sessions. There, look words up, but only a few chosen ones: the ones that keep coming back or block the sentence. Write them down and review them separately, as Pellicer-Sánchez and Schmitt suggest when they recommend explicit tasks alongside reading.

Give your free reading some structure. The 2025 meta-analysis found larger effects when text choice was limited and some form of accountability was built in. A short shelf of graded readers at your level and a log of what you read meet both conditions.

The novel you love can wait on the nightstand while easy books give you the speed to enjoy it.

Try this today: time yourself for ten minutes with a graded reader and read without touching the dictionary; if you stop more than five times on a page, drop a level tomorrow.