Corpora: help requested in locating corpora

[Tomoko Watanabe]

Dear list subscribers,

I am looking for (preferably electronic) corpora, in English and in
Japanese, which allow a search for a particular grammatical construction.
Any information you could offer would be much appreciated.

The construction in question is Object Topicalization.  An example is below.
        These issues, I will discuss later.

Is there any tagged English corpus which is ready for a search of this
construction?  If not, is there one which can be easily tagged for such a
search?

As for Japanese, I am not aware of any corpus on which a linguistic search
could be run, but I would appreciate it if any of you could correct me and
tell me of one.

Thank you very much for your attention.

Tomoko Watanabe
Research Centre for English and Applied Linguistics
University of Cambridge, UK