As the preceding entry on historical linguistics and language change has shown, the structure of present-day English—its sound system, its grammar and its vocabulary—is the result of almost 1,500 years of historical evolution. Many factors—both internal to the linguistic system and external (historical, social, cultural)—have influenced this process, their influence varying in strength from period to period and depending on the particular structural domains affected. The overall result has been a structural profile of present-day English which is rather different from the historically related languages of Europe with which it has been in continuous contact.