I have long thought: 1. that to be + past participle is a passive form. 2. that only transitive verbs can have passive forms. 3. that to go and to come are intransitive verbs. Yet: After he is gone May 10th 2007 From The Economist print edition Life after Tony Blair will have some surprises 'They are come to visit us at Christmas, out of the world where all live to God; and to tell you some of their old fairy tales, which they loved when they were young like you.' From Heroes, Charles Kingsley. We come across such examples all the time. What form of the verb is it?