Interesting website to practise listening (basic to low-intermediate). With quizzes and worksheets.

Type in a phrase and it plays different scenes from movies where that phrase is used in context. Awesome!

Lang-8 is a free language-exchange social network. Just write a journal in any language you're learning, and it will appear to native speakers of that language. They'll correct it and leave useful comments and feedback. In return, you check other users' journals written in your native language

The page claims to be a listening "game" but it's really just a simple fill-in-the-gaps exercise. Files are classified according to level (easy, medium and advanced) and categories (comedy, education, games,…).

A website with a sense of humour explaining the meaning of some false friends.

Story tools has a collection of tools to analyze your writing. For example, you can paste your essay here and check "readability" (it analyzes your sentences (long/short), use of passives, articles, verbs, etc) or clichés, word count, etc. It also works well to help you create your own stories (use the "story idea generator" button). Why don't you try using some of these tools before handing in your writing to your teacher? :)

Useful to expand your vocabulary or to see a word used in context (use "Example sentences" for this purpose).

Have you ever wondered how reading different genres could improve different aspects of your writing? 

The purpose of this website is 3-fold: Lookup pronunciation of a name. Submit pronuncation of a name so that others can pronounce it correctly. Request pronunciation of a name that you don't know and would like to find out.

English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

Good to review verb forms. Basic level

Various articles that aim to teach students how to write better.

Writer's Digest offers information on writing better and getting published. The site also includes community forums, blogs and huge lists of resources for writers 

A very useful reference for classic errors and helpful hints with a terrible site navigation.

A collection of common errors in English, with detailed explanations and descriptions of each error.

This guide is based on the style book which is given to all journalists at The Economist. The site contains various hints on how to use metaphors, punctuation, figures, hyphens etc. Brief and precise.

This site contains 26 short articles with writing tips about ampersands, punctuation, character spacing, apostrophes, semicolons and commas, difference between i.e. and e.g. etc.

An older, yet very useful site that will help you to improve your writing on word & sentence level, paragraph level and also essay & research paper level.

A quick and useful crash course in English punctuation. 

Dicionario da alimentación e restauración. Galego-castelán-inglés.