Deutsch · B1 · grammar · 4 minutes
Infinitive clauses with zu
Use zu + infinitive when one clause depends on another verb, adjective, or purpose phrase.
Understand the choice
Infinitive clauses compact an action when their understood subject matches or is recoverable. The placement of zu reveals verb structure: zu lernen, anzurufen, aufzustehen, but not after modal verbs.
Core rule: Dependent infinitives often use zu; with separable verbs, zu appears between prefix and stem: aufzustehen.
Notice it in context
Ich versuche, jeden Tag früher aufzustehen.
I try to get up earlier every day.
Versuche is finite; the comma introduces the dependent action; auf-zu-stehen keeps the separable verb structure.
Es ist wichtig, die Frist einzuhalten.
It is important to meet the deadline.
Zu is inserted into separable einhalten: einzuhalten.
Sie fährt nach Berlin, um ihre Schwester zu besuchen.
She travels to Berlin in order to visit her sister.
Um…zu states purpose with the same understood subject.
What to remember
- Verbs ending -ieren do not separate but take zu before the infinitive: zu reservieren.
- After modals, lassen, sehen, and hören in common patterns, no zu is used.
Common trap: Do not write zu aufstehen. Insert zu inside the separable infinitive: aufzustehen.