Google Translate: probably the most useful site ever for learning new words and expressions when reading English material on the web. It's true that the translations are often bad, but it's getting better and better. Remember that if you can't understand an individual words, you might need to translate the whole phrase or sentence. For example, in the expression "every now and then" you may understand every word individually but together it means "from time to time". If you use chrome, there is a very useful extension that you can download that can automatically translate words or phrases that you highlight.
Reverso Context: http://context.reverso.net/translation/ It's really important for learning new words to understand how they work in sentences. Context is very important for both remembering the words and how to use them. If you just try to memorize a word and its translation, you are wasting your time. Before the Internet, it was really hard to find good contexts. You would learn a new words and hope that you would meet it later somewhere in a book or newspaper article. Now you can easily find the words used in context. In addition to using Reverso Context, you can also try googling the word or expression and also use google image and YouTube. Imagine you're on a wild safari and that the words and expressions are wild animals, and you're meeting them in their natural habitat. The important thing is to have fun and enjoy learning new words!
Forvo: https://forvo.com/ is a useful site for learning how to pronounce words in English, or any other language, properly. All the words are pronounced by real native speakers. If you register, you can also request somebody to pronounce something if you don't find it on the site.
Flashcards Deluxe: This is an app for either iOS or Android. It's not free, but it is the best one I have found. There are other free apps that do the same thing that you can try out if you don't want to spend money. You can also do it the old-fashioned way and make physical cards. Flashcards are the best way to learn lots of vocabulary fast. The best way is to write on one side the word, and under it the sentence using the word. You can use either the sentence from what you are reading, or a sentence from Reverso Context. The important thing is that it is a good sentence that lets you guess what the word means. On the back, you can write either the translation, or a definition in English. Don't forget to write a sentence down using the word, that is the most important thing. Learning words without context is a big waste of time!
LingQ: https://www.lingq.com This is a very useful site for learning languages. It has a huge library of texts in English. At first all the words are highlighted blue, meaning they are unknown. You click on the words that you know and they get turned into lingqs, which are what they call flashcards, that you can review later. In addition, all the texts have audio, so you can listen to them as well. The only bad thing about the site is that you only get to make 20 lingqs for the free account.
