Breakdown of Das auswendig zu lernende Gedicht ist kurz.
sein
to be
lernen
to learn
kurz
shortly / short
zu
to (infinitive marker)
Questions & Answers about Das auswendig zu lernende Gedicht ist kurz.
What exactly is zu lernende and how does it mean "to be learned"?
This is the Gerundivum, a structure that expresses a passive obligation. It is formed by putting zu before the present participle of a verb (here, lernend) and adding an adjective ending. It acts as a compact way to say "that must be learned" or "to be learned".
Why is the phrase written as auswendig zu lernende rather than one single word?
The verb phrase is auswendig lernen (to learn by heart), which consists of two separate words. When forming the Gerundivum, zu attaches directly to the main verb's participle, forming zu lernende. The modifying word auswendig remains a separate word right in front of it. (If it were a true separable prefix verb like vorlesen, it would be one word: das vorzulesende Gedicht).
Why does lernende end with an -e?
Because it sits directly before the noun Gedicht, the entire Gerundivum acts as an attributive adjective and must take standard adjective endings. Since Gedicht is a neuter noun in the nominative case preceded by the definite article Das, it takes the weak adjective ending -e.
How could I express this exact same meaning using a normal relative clause instead?
You could say: Das Gedicht, das auswendig gelernt werden muss, ist kurz. The Gerundivum is simply a more compact, slightly more formal alternative to using a passive relative clause with the modal verb müssen.