Collins CoBuild's Web concordancer

The Collins WordbanksOnline English corpus is composed of 56 million words of contemporary written and spoken text. To get a flavour of the type of linguistic data that a corpus like this can provide, you can type in some simple queries here and get a display of concordance lines from the corpus (restricted to 40 instances).

Hong Kong Virtual Language Center's Concordancer

It contains a number of old but still popular corpora like LOB and Brown and provides a fuller context for searched items. It can also display up to 1500 instances of searched items.

British National Corpus