1. One or more computer-readable media having computer-executable instructions embodied thereon for performing a method of expanding and indexing a semantic relationships between words within a sentence, the method comprising: receiving a first electronic document having content that includes text; breaking the text into one or more sentences; determining a first role for a word in the sentence; determining that the word has more than one potential role; assigning a second role to the word; and storing the word with the first role and the second role in an index that associates the word and the sentence with the first electronic document, thereby allowing a search engine to match the first electronic document with a search query that includes similar words having similar roles.