How to choose the right reading level

How many unknown words is too many?

The usual benchmark is coverage, the share of the words in a text you already know. Paul Nation summarises it simply: at 98% coverage there is about one unknown word in every 50, which he treats as ideal for reading without help; at 95% it is one in 20, roughly one per two lines of print. He adds that 98% assumes no dictionary, and that slightly lower coverage is acceptable when you have support. Our page on extensive reading covers the studies behind these figures.

Applied to the average length of a Contos chapter, that gives a rough budget of unknown words per chapter:

If you are tapping well beyond the 95% column, the chapter is probably too hard to enjoy. If you barely tap at all and the story feels slow, try the next level up.

What does the same story look like at each level?

Contos's flagship Spanish series, The Building on Calle Sol, is written separately at all four levels: the same building, the same doorkeeper and the same young tenant, Alba. Comparing the opening of chapter 1 at each level shows what moving up actually means.

A1 sticks to short sentences in the present tense. A2 adds detail and set phrases such as acaba de (has just). B1 moves the story into past tenses, and B2 builds long sentences with clauses inside them. The A1 version is free to read on this site.

The Council of Europe's self-assessment descriptions give a similar picture from the reader's side. At A1, you can understand familiar names, words and very simple sentences, like those on notices and posters. At B1, you can understand texts made up mainly of high-frequency, everyday language, and descriptions of events, feelings and wishes in personal letters.

How do you test a level in ten minutes?

1. Pick the level whose description sounds most like you. If you are unsure, our page on CEFR levels describes each one.
2. Open chapter 1 of a series at that level and read it once without tapping. Can you say what happened?
3. Read it again, tapping each word you can't work out. Count the taps and compare them with the table above.
4. Repeat with chapter 1 at the next level down or up, depending on how the first one went.
5. Keep the level where you understood the plot on the first read and stayed within the 95% budget on the second.

Taps aren't a perfect measure. You might tap a word you half knew, or skip one you guessed from context. As a rough guide, though, they are more honest than a feeling. For another rule of thumb, see Rob Waring's two-minute page test on our graded readers page.

When should you move up or drop down?

Contos has no placement test. You choose A1, A2, B1 or B2 when you start, and the app moves you up when your known words reach 500, 1,500 and 4,000. A word counts as known when you mark it so in the reader or when its flashcard reaches the 16-day review step. You don't have to wait for that: the library lets you filter series by any level, and a "Ready for more?" row shows series from the level above yours.

• Move up when chapters at your level feel easy, you rarely tap, and you find yourself skimming. If the next level feels like a wall, our page on the intermediate plateau explains why.
• Stay when you follow the plot but still tap a few words per paragraph. That is the zone the research points to.
• Drop down when you need the translation to know what happened, or when reading feels like decoding rather than following a story.

There is no shame in reading below your level. Krashen argued that input only needs to be roughly tuned to the learner, and easy reading still brings familiar words round again; our page on i+1 explains the idea.