German uses three parallel infinitive constructions to express purpose, manner, or alternatives, all built with ... zu + Infinitiv. The most important is um ... zu, meaning "in order to". It expresses purpose but requires that the subject of the main clause and the infinitive clause be the same: Ich lerne Deutsch, um in Deutschland zu arbeiten. By contrast, the conjunction damit is used when the two clauses have different subjects: Ich spreche langsam, damit du mich verstehst. The two constructions ohne ... zu ("without doing") and anstatt ... zu ("instead of doing") follow the same infinitive pattern: Er ging weg, ohne sich zu verabschieden and Anstatt fernzusehen, solltest du lernen. After impersonal expressions such as Es ist wichtig, the infinitive with zu follows: Es ist wichtig, regelmäßig Sport zu treiben.
With separable verbs, the zu is inserted between the prefix and the verb stem, written as a single word: an|rufen → anzurufen, ab|schließen → abzuschließen. Compare: Ich habe vergessen, dich anzurufen ("I forgot to call you") and Ich habe vergessen, die Tür abzuschließen ("I forgot to lock the door"). Mastering this placement is essential because separable verbs are extremely common in everyday German, and learners frequently write the wrong form such as zu anrufen.
Indirect questions embed a question inside another sentence. For w-questions (wo, wann, wie, wer...), the question word itself stays at the front of the embedded clause and the verb moves to the end: Können Sie mir sagen, wo der Bahnhof ist? (Direct: Wo ist der Bahnhof?). For yes/no questions, German uses ob ("whether/if"): Ich weiß nicht, ob er morgen kommt. Note that in indirect questions, separable verbs rejoin into one word at the end: Wann fährt der Zug ab? → Wissen Sie, wann der Zug abfährt?. A related conjunction is sodass, which introduces a result clause: Er hat lange geübt, sodass er die Prüfung bestanden hat. Together, these structures allow you to express purpose, alternatives, embedded questions, and consequences with precision.