Abstract
In this paper, we attempt to determine the underlying word order of Old English (OE) including the position of INFL. We will show that Early OE and Late OE are SOVI (S-VP-I) and SIOV (S-I-VP) languages, respectively, pointing out a striking difference in the distribution of stressless pronouns between them. On the basis of the underlying word order change in the history of English, we will propose a principle regulating word order change, which we call here the Principle of Parameter Percolation (PPP).
