Breakdown of Der Hund fand den Rucksack, aber er wird kein Lebenszeichen gerochen haben.
er
he
der Hund
the dog
haben
to have
aber
but
Questions & Answers about Der Hund fand den Rucksack, aber er wird kein Lebenszeichen gerochen haben.
Why does the second part of the sentence use wird ... gerochen haben (will have smelled) if the dog's search already happened?
This is the Futur II (Future Perfect) tense. In German, it is very commonly used to express an assumption or strong probability about a past event. Even though it translates literally to 'will have smelled,' a more natural meaning here is 'he probably didn't smell' or 'he must not have smelled.'
What is the exact word order rule for the Futur II verbs in this clause?
In a standard main clause, the conjugated verb wird takes the second position. The other two verb parts are pushed to the very end of the sentence. The past participle (gerochen) comes first, immediately followed by the infinitive auxiliary (haben in this case).
Why does the sentence use fand instead of hat gefunden for 'found'?
fand is the Präteritum (simple past) of finden. While you will hear hat gefunden more often in everyday spoken German, written German (like stories or news reports) frequently uses the Präteritum to describe past events.
Why is kein used here instead of nicht?
kein is used to negate nouns that either have no article or would use an indefinite article like 'ein'. Since the sentence negates a noun, German uses kein Lebenszeichen ('no sign of life') rather than negating the verb with nicht.