My students constantly ask me if it is okay to use google translator. Sure it is! We can't leave in a bubble! Google Translator is here to stay, but it can also be problematic. First because we don't always get the right word for the context and second because you can just get lazy! Seriously! You just get the answer immediately, no effort, no thinking process, and...as a result...no learning! How many times have you checked a word and then just forgot five minutes later?
With that in mind, I would suggest a good old dictionary, but, this time, in a new style! I personally really like
The Free Dictionary. It is a monolingual dictionary ( offering many different languages) but also a great place to practice your vocabulary.
As any dictionary , you get definitions, the word class ( noun, adjective, verb, etc), and examples. But if you click on the symbols, you also get the British and American pronunciation.
And more ( I'm sounding like an infomercial here!) you also have synonyms, opposites and related words. Great when you want some variety in your text!
Apart from that the site offers some other activities, such as word of the day, spelling bee, hangman, article of the day, etc.
You can register to the site, this way, everyday those info by email or like them on facebook and G+