18. The system of claim 13 , wherein the system further comprises instructions to determine the likelihood based at least in part statistics derived from the plurality of reference subjects and associated reference actions found in the corpus of textual documents.
13. A system including memory and one or more processors operable to execute instructions stored in the memory, the memory comprising instructions to: identify, in a segment of text, a subject and an action performed by the subject; determine a likelihood that the action is performable by a class of subjects with which the subject is associated, the likelihood based at least in part on a plurality of reference subjects and associated reference actions found in a corpus of textual documents; and provide an indication of the likelihood.