One of my former students once told me what her ingenious strategy is for using “zu” in German. “I just stick it at the end to make the sentence sound German”. Unsurprisingly, as always in the German language, there is a rule for when we use zu- intuition won’t do the trick.
Many students first learn about zu as a dative only preposition. I have covered dative prepositions in German elsewhere, in this blog post I focus on the word zu in combination with verbs.
First, let’s clarify where zu is never used- after modal verbs and auxiliary verbs like werden und würden. So können, wollen, sollen, dürfen, möchten, mögen, müssen, and the aforementioned verbs only go with the infinitive of the verb without zu before it.
E.g. Ich muss meinen Unterricht vorbereiten.
Er wird im Sommer in Urlaub fliegen.
Sie würde lieber zu Hause bleiben.
Let’s now look at two situations in which zu is used in subordinate clause. The first situation is in combination with the conjunctions “um...zu”, “ohne...zu”, “statt...zu”.
E.g. Um mein Griechisch zu verbessern, muss ich mehr Vokabeln lernen.
Ich gehe selten aus dem Haus, ohne vorher meinen Schlüssel zu suchen.
Sie geht zu Fuß, statt den Bus zu benutzen.
The trickier situation in which zu is being used in a subordinate clause is after verbs that trigger a so-called infinitive construction. The most common verbs and phrases are:
Anfangen
Aufhören
Anbieten
Beginnen
Beabsichtigen
Die Absicht haben
Beschließen
Entscheiden
Sich entschließen
Versprechen
Versuchen
Bereit sein zu
Ich fange an, eine E-Mail zu schreiben.
Wir beabsichtigen/haben die Absicht, einen Urlaub zu planen.
Sie beschließen/entscheiden sich/entschließen sich, ihr Auto zu verkaufen.
Ich versuche, mehr Zeit zum Joggen zu finden.
The good news is that the zu often translates into English and reminds you that there is a zu in the infinitive clause. So I hope you see that the German use of zu is not as random as my student assumed. One final remark on commas in German. Rules have changed in the last 25 years. Nowadays, it's optional to use a comma before the infinitive clause. But I'm old school, so I use commas there to distinguish the main from the subordinate clause.
Learn more about how to structure German sentences (word order) and subordinate clauses in the language on my blog. There, you will also find posts about the difference between nachdem and danach, bevor and vorher, when to use zu in German sentence, an explanation of how to use um...zu and damit, and a post about the use of als and wenn in German. Of course, we also have articles on other grammar topics, such as reflexive verbs and how to use them in German, direct and indirect questions in the German language, verbs with prepositions, the Konjunktiv in German, adjective ending rules in German
