Free download ELT Resources:

• WordNet Dictionary
  WordNet is an online lexical reference system whose design is inspired by current psycholinguistic theories of human lexical memory. WordNet was developed by the Cognitive Science Laboratory at Princeton University under the direction of Professor George A. Miller.
  
• Learn English Online with English Portal
  Learn English online - Free exercises, idioms, common abbreviations, slang, proverbs and much more.
  
• One Stop English
  Materials for teaching and learning Vocabulary, Business English, Grammar, and many more.
  
• The Academic Word List
  The words that university students need to know; based on Coxhead, Averil (2000) A New Academic Word List. TESOL Quarterly, 34(2): 213-238.
  
• Merriam-Webster
  Merriam Webster Online Dictionary and Thesaurus.
  
• English Grammar Reference
  The free online reference and guide for English grammar. It is a great resource for both English language teachers and English language learners.
  
• English Grammar Exercises
  Free online exercises in grammar. Test your knowledge on Conditional sentences, Tenses and a lot more. See the result instantly online.