#4Corpus-based Reference Tools

VLC Concordancer
http://vlc.polyu.edu.hk
NTNU Concordancer and Collocation Retrieval System (CCRS)
http://140.122.83.246/cwb/

Both of these tools are helpful to me.
because I always put the words together but maybe in the wrong way
It can let me search the correct word or collocation before I use.

Compare with dictionaries
Corpus-based Reference Tools
the data of this are based on daily speak or writing.
So it include formal and informal usage both.
You have to differentiate the result maybe with other tools.
and you can choose information from a lot of database.
American or British,make your english more local.
The information of corpus may update more often than a dictionary

Dictionaries
The dictionary offer more detail than corpus.
The phonetic transcription,meaning,example and something else.
But the information have been compiled already.
Have little chance to be updated,
So it may contain some old fashion words.
If you notice the time of corpus collected,you can avoid this problem.
But you still better use a dictionary when you get a new word first time.

Using these tools
I think the problem is you have to conclude the result.
Just like the problem ever be mentioned,formal or informal.
It just help you listing all the words that people ever uesd.
But I also think it's not a big problem :P