Dictionaries 

• Wordreference: The most popular online dictionary of all times!
• Urban Dictionary: Try looking up new words.
• Merriam-Webster: Visual dictionary online.
• Oxford Learner's Dictionary: The traditional Oxford Dictionary now online.

Listening and video watching

• Real English :graded lesson videos based on real English interviews.
• ESL Video : multiple choice listening comprehension exercises.
• English Yappr : choose a video by topic and read the subtitles simultaneously.
• Podcasts in English: listening exercises with transcript and worksheets.
• British Council. Listen and watch: listening comprehension exercises.
• Breaking News English: listen and reading comprehension exercises.
• Videojug: a repository of videos about all kind of subjects.
• Listen a minute: One minute audios with script and exercises.
• Esl-lounge: listening exercises (elementary, intermediate, advanced.)
• Lyricstraining: improve your listening skills through songs!
• Voices in the dark: Audio books and stories read aloud by real people for free!
• Storynory: Free audio stories.
• Ororo TV: Learn English watching TV series and movies for free!
• Rebeats: Great music in English with enjoyable tasks

Vocabulary and Grammar

• a4esl.org: English vocabulary graded quizzes.
• Bon's tips: Website by English teacher Manuel Bonillo to practise grammar.
• British Council: topic-based vocabulary exercises.
• Quiznet - BBC Learning English: multiple choice vocabulary quizzes.
• La mansión del Inglés: Website to practise grammar through games.
• engVid: Learn English grammar through videolessons.
• Language guide: Learn English grammar through interactive games.
• Learn English, Feel good: multiple vocabulary quizzes by topic.
• Learning Chocolate: Vocabulary learning platform with exercises classified by topic, including images and audios.
• ompersonal: free online school to learn English and pass English tests.
• English Club: vocabulary quizzes (elementary-intermediate-advanced).

Reading

• ESL Reading lessons: reading comprehension exercises.
• Project Gutenberg: Virtual library for free English resources.
• My English Pages: reading comprehension exercises.
• Gocomics: American website for comics.
• Esl-lounge: reading exercises (elementary, intermediate, advanced.)
• Newspapers and Magazines: The Guardian, The Times, Daily Mirror, The Sun, New York Times, USA Today, Time, Forbes.

Writing

• My English Pages: writing tips for English learnners.
• Spell Up: Online game for Chrome that helps improve pronunciation and spelling.
• Listen and write: Dictation website that allows students to improve their listening and writing skills as they listen and write songs, poems, news and many others.
• Blog para preparar el writing de la EOI: writing tips to prepare for your "Certificación" exams.
• Sample Writing for English Exams: Prepare online with free writing resources.
• PenPal World: Site where you can meet  pen pals from every country on the planet!

Speaking

• Aprende Inglés Sila: Web to improve pronunciation.
• Duolingo: Web and app to learn English, including speaking, in an interactive way.
• italki: Get one-on-one online lessons with native language teachers and connect to people around the world.
• Vocaroo: Easy and quick way to share online recorded messages.

Pronunciation

• Guía ESL de sonidos vocálicos en inglés: Learn vowel combinations in English.
• Forvo: Listen to English words with different accents.
• Vaughan Radio: Online radio to practise pronunciation with listen and repeat exercises.
• Subinglés: Website to learn English through singing!
• English Pronunciation: App for Android to learn pronunciation.
• Otterwave: App for IOS to learn pronunciation.
• The Speech Accent Archive: Set of speech samples from a variety of language backgrounds.
• Phonetics Focus: Learn phonetics in an enjoyable way!

Useful apps to learn English on your mobile!

• Ejercicios de Inglés
• LearnEnglish Grammar
• Gramática de Inglés
• Inglés para todos
• Inglés Gramática

• The Cavern: blog do nivel Intermedio
• Have Fun with English: blog do nivel Intermedio
• English is FUNtastic: blog do nivel Avanzado
• Have fun with English C1.2: blog do nivel C1.2