Comprehensible input: the idea behind DuoText

Krashen, a linguist, argued that we acquire a language by understanding messages in it, not by studying rules. The input has to be comprehensible: a little beyond what you already know, but still mostly clear from context. He calls that level “i+1”. Too easy and you learn nothing new; too hard and you understand nothing, so you learn nothing either.

He also stressed that the input should be interesting. If you want to keep reading, you read more, and reading a lot is what builds the language.

Later vocabulary research, by Paul Nation and Batia Laufer among others, put numbers on “mostly clear”: readers cope best when they already know roughly 95 to 98 percent of the running words. Those figures are theirs, not Krashen’s, but they describe the same sweet spot. Below it, a page is a puzzle. Above it, you just read.

The theory is easy to accept and very hard to practise. You need a text where you understand nearly everything, that still teaches you something, and that you actually want to keep reading. There are only so many books, and very few sit at your exact level on a subject you care about.

Graded readers are at the right level, but they are rarely gripping. Real novels are gripping, but for a long time they sit far above your level. Most people fall into the gap and quit.

Reading with the translation beside each paragraph is what first got me reading. But it is support, not the method. Krashen has not endorsed it, and I don’t claim he has. The honest version is this: a parallel text and a quick look at a word’s meaning help you stay in a text that is a bit too hard, and that is worth a small extra advantage.

It does not rescue a text you cannot follow. If you understand almost nothing, the translation turns reading into translating, and the input stops being comprehensible. You have to understand most of the page on your own; the translation only covers the rest.

We publish free classics in the library, but we don’t think you should read them because they are good for you. Read what you enjoy. That is why we also write series with no literary ambition. They are meant to be easy to start, easy to understand, and hard to put down.

Summer at the Lemon House is one of them: a romance with some drama on Lake Garda, told in ten short episodes, one evening each, at an A2 level. It is a little silly on purpose. Think of a streaming show you watch one episode at a time: the point is that you come back tomorrow.

Do pictures help?

Some of these stories have illustrations, because the common view is that pictures make reading more inviting, especially for younger readers. I don’t know yet whether they help people acquire a language. We are testing it, and I would rather say so than guess.

A single series helps only the readers it happens to fit. What we are working towards is a story for each reader: one that stays near the 95 percent mark as you improve, built from your level, the words you don’t know yet, and the pace you read at. A long series that begins at A1 and grows towards C1, one short episode a day, with you choosing the kind of story.

The deeper goal is a series built to keep you curious: a story you want to follow so much that you stop thinking about the language and just read, and learn it without noticing. Keeping that interest alive over hundreds of episodes, at a level that rises with you, is the hardest part, and it is what we are preparing now.

That is the plan, not a finished product. Today you can read the library and the series that are already published, with the translation beside every paragraph. The rest we are building, and telling you as we go.

1. Pick a story at the level where you understand most of the page without help.
2. Read in the language you are learning, and glance across only when you are stuck.
3. Pick stories you want to continue, not ones you feel you ought to read.
4. If you look across for most sentences, go one level down. If you never need to, go one up.

More on the practice itself is in the guide to learning a language with stories.