EUROCALL: European Association for Computer Assisted Language Learning


Steve Ridout


1. Introduction

Reading is a key skill in language acquisition. With engaging content it can be very enjoyable and motivating. The problem is the lack of interesting texts at suitable difficulty levels. Reading texts requires a lot of work on the part of the learner, both looking up definitions and making sense of the grammar. This work can turn reading into a chore and make challenging texts impossible to follow.

Readlang attempts to help by:

  • reducing the work and distraction involved with reading difficult texts
  • optimising the acquisition of useful vocabulary using a spaced repetition system
  • recommending sources of content suitable for beginner learners

This article explains how the site currently works to achieve these goals. The site is in beta and rapidly evolving. This is a snapshot of how it functions at this stage.


This 2 minute video gives an overview of how the site works:

Reading aids

Readlang provides the following reading aids. These allow the user to focus on reading in their target language, and for the parts they don’t understand, it helps them figure out the meaning with as little distraction as possible, hopefully allowing them to continue enjoying the content.

Inline translations

Clicking on a single word replaces it with a translation from Google Translate to the learner's first language.

Clicking on adjacent words, or dragging across a phrase, will replace them with the translation of the entire phrase. This is especially useful for collocations like phrasal verbs, verb conjugations with multiple words, or idioms which can’t be translated literally.


Figure 1. Readlang functionality.


External dictionaries

A set of translations and/or definitions from an optional external online dictionary, which varies depending on the langauge. The following languages currently have external dictionaries:

Reading environments

Web Reader

This is implemented as a Chrome extension or a bookmarklet and allows the user to use the Reading aids from any other page on the web. Once loaded, a toolbar appears allowing the selection of the user’s first and target languages, and allows disabling the reading aids in order to click on links within the page.

The external dictionary in the Web Reader is optionally presented inside a separate window. Every time a word or phrase is clicked the external dictionary will update itself.


Figure 2. Example from Readlang.


Online eReader

This presents plain text content in a paginated format. The user’s position in the text is stored so that when they log in from any device they can continue reading from where they left off. The external dictionary is optionally presented in the sidebar.


Figure 3. Readlang sample page.


Sources of texts for the online eReader

Users can read texts from multiple sources:

  • Web Importer - Extracts the content of any web page in plain text format.
  • Enter plain text - Type or paste plain text directly into a form.
  • Upload plain text file - Upload a plain text file. PDF or ePub files can be converted plain text format first using software such as the open source Calibre.
  • Readlang’s public library - A crowd-sourced database of texts shared by Readlang users.

Difficulty grading

In languages for which word frequency lists are available, all uploaded texts are analysed in order to estimate their difficulty level on the Common European Framework of Reference for Languages scale. This is a custom algorithm which gives a reasonable indication of difficulty but isn’t perfect and will be gradually improved over time.

Popular websites

The database of user imported webpages is analysed to compile a list of recommended websites for learners of each language to find new content. For example, the top 5 sites among French users are:

Vocabulary building

Every word or phrase translated in Readlang is saved to your account, along with the context sentence. This allows you to either export your word lists to other tools such as Anki or use the flashcards and spaced repetition system built in to Readlang.


Readlang allows the user to review flashcards in sessions of 10, 20 or 30 cards. Initially, the context sentence is presented, with the relevant word underlined, and the user must guess the meaning of the word. They click to reveal the translation. Users are highly recommended to verify and modify the translation at this point, since the Google Translate results will obviously not be 100% accurate. To aid them with this, an external online dictionary is presented with alternate definitions if available.
The spaced repetition system is modelled after other software such as SuperMemo and Anki. Upon revealing the translation on the flashcard the user is asked whether they remembered the word and given a choice of four options: “Not at all”, “Almost”, “Yes, just”, and “Perfectly”. If they remembered the word, its next appearance will be scheduled in progressively further dates in the future, whereas if they failed to remember it will be shown again in this session, and then again the following day.
After successfully guessing the meaning of a foreign word, each subsequent time the flashcard appears it will be reversed, so the user is shown the translation in their first language and asked to guess the word in their target language, a more challenging problem.

In an improvement over other more general spaced repetition algorithms, Readlang uses the frequency of each word in a representative corpus of texts for each language to prioritise its position in the flashcard lists. This helps the user optimise their time by learning the most useful words first, and is particularly useful when the user’s list of words greatly exceeds the amount of words they have time to practise.

Audio Pronunciation

Where supported by the Microsoft Bing text-to-speech API, audio pronunciation of words and phrases is available from the reader page and the flashcards page.

Video synchronisation

Readlang allows YouTube videos to be synchronised to a transcription so that learners can work on improving their listening skills, see Watching YouTube synchronised texts in Readlang for a demonstration. The currently spoken word is highlighted so that the listener doesn’t get lost, and any word in the text can be clicked on to start the video from that position.

Users may upload transcriptions and synchronise them to YouTube videos themselves, see Synchronising YouTube videos yourself for a demonstration on how to synchronise videos yourself.

Supported Languages

The page shows statistics for each of the currently supported languages. Currently the most popular language is French with over 52,000 flashcards generated so far, closely followed by Spanish with over 46,000.

Suggested use

Readlang has been developed as a tool for independent study. However, teachers may find it useful to upload texts or YouTube transcriptions to share with their students, and to encourage them to use the site to read content they are interested in for pleasure in their own time.

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Universitat Politècnica de València

e-ISSN: 1695-2618