Corpus resources

Word and Phrase

Word and Phrase focuses on collocations:
http://www.wordandphrase.info/frequencyList.asp

It shows:

• The rank by frequency in the corpus
• Definition
• Collocations by frequency
• The relative frequency in spoken, fiction, academic, newspapers, magazines and well as the number of occurrences
• Examples in use

It allows you to sort on a variety of parameters. Especially useful is the ability to look up collocations quickly.

The Corpus of Contemporary American English

This is the largest freely available corpus. It consists of 450 million English words from the period of 1990 to 2012. 

http://corpus.byu.edu/coca/

N-grams

http://www.ngrams.info/