Verbs That Use sein with Participles
Many people have trouble following the dialogue in a Shakespearean play. The major reason for that is not the general vocabulary of the language used in Shakespeare's time, but the verbs.
English has changed a lot since Shakespeare's lifetime. Among other things, we no longer use “thou,” “thy,” “thine,” or the conjugations that go with “thou.” Nowadays many theatergoers have to listen carefully to understand a line such as, “Couldst thou but linger a moment longer.” It's not a question, and it simply means, “I wish you'd stay a couple of minutes more.” And there is the famous, “Wherefore art thou Romeo?” That is a question, but Juliet doesn't want to know where Romeo is. She's looking right into his face when she says it. She wants to know why he has to be called Romeo—a member of the family considered to be enemies by her kin! How about this one? “His Majesty just this moment is come from the hunt.” Does that combination of words “is come” strike you as strange?
Speakers of modern English usually get the gist of such lines, but sometimes it takes some extra thought. The reason is simple: Modern English conjugations are simpler, and we no longer have two auxiliary verbs in the present perfect tense.
In earlier times, certain verbs used “have” with a past participle to form the present perfect tense—just like today. But other verbs—verbs of motion—used “to be” with a past participle to form the present perfect, for example, from the King James version of the Bible, “He is risen.” That sentence in modern English would be “He has risen.”
The whole point of this explanation is to let you know that German isn't doing something wacky in the present perfect tense when it uses the verb sein with a past participle. It's just doing what was done in English a few centuries ago.