Futur II and speculation

This is the last piece of B1 grammar, and it is mainly one you need to recognise. You will meet it constantly in speech and almost never need to build it under pressure.

werden + Partizip II + haben/sein. It usually means "has probably already happened", not "will have happened by then".

• Er wird schon angekommen sein.

  He will have arrived by now. / He has probably already arrived.

  ankommen takes sein, so sein comes last

• Sie wird das vergessen haben.

  She will have forgotten that.

  vergessen takes haben

• Der Zug wird wahrscheinlich schon abgefahren sein.

  The train has probably already left.

• Sie werden die Nachricht gelesen haben.

  They will have read the message.

The auxiliary at the end is the same one the Perfekt would use. If you know ist angekommen, you know it is angekommen sein.

Word order: werden holds position 2; the Partizip II and the infinitive haben/sein close the sentence, in that order.

Four words tell you a guess is being made. They very often sit inside the sentence:

And here is the part worth remembering: you can say the same thing without Futur II, using grammar you already have.

• Er ist wahrscheinlich schon angekommen.

  He has probably already arrived.

  Perfekt + a signal word — what most people say

• Er wird schon angekommen sein.

  He will have arrived by now.

  the same guess, marked by the grammar itself

Both are correct and both are common. Understand the second; produce whichever you like.