how fast

An interrogative phrase used to ask about speed, velocity, or rate of movement/change. Note: 'How fast' is primarily an interrogative adverbial phrase consisting of 'how' + the adjective 'fast'. When used before nouns like 'speed', 'rate', or 'pace', it functions as a complex determiner phrase modifying those nouns. This entry focuses on its determiner-like usage with nominal complements.

• 🇩🇪Fragephrase zur Erfragung der Geschwindigkeit, Schnelligkeit einer Bewegung oder des Temps von Veränderungen. Hinweis: 'How fast' besteht aus dem Adverb 'how' und dem Adjektiv 'fast'; in Verbindung mit Substantiven wie 'speed', 'rate' fungiert es als komplexe Bestimmungsphrase.

1. Interrogative determiner (physical speed) A1 formal

   Used before nouns denoting motion or velocity (e.g., 'speed', 'pace', 'rate') to ask about measurable physical speed of movement.

   • How fast a speed can this car reach?
   • How fast a pace are you planning to run?
   • How fast a rate does the river flow?

   🇩🇪Interrogativdeterminativ (physische Geschwindigkeit)

2. Interrogative determiner (rate of change/progress) B1 formal business

   Used before abstract nouns to ask about the rate, tempo, or rapidity of a process, change, or development.

   • How fast a growth rate is sustainable?
   • How fast a change can the system handle?
   • How fast a progress have we achieved?

   🇩🇪Interrogativdeterminativ (Änderungs-/Fortschrittsgeschwindigkeit)

3. Adverbial usage (standalone speed inquiry) A1 informal

   Used without a following noun to ask about speed directly. The noun is implied by context. (Note: This is the most common adverbial usage, included for completeness).

   • How fast can you type?
   • How fast does the train go?
   • How fast did you finish the race?

   🇩🇪Adverbiale Verwendung (selbstständige Frage nach der Geschwindigkeit)

4. Indirect question usage B1 formal

   Used to introduce a noun clause that reports a question about speed, functioning as the object of verbs like 'know', 'ask', 'wonder'.

   • I wonder how fast he can run.
   • Do you know how fast the download will be?
   • Tell me how fast you need this done.

   🇩🇪Verwendung in indirekten Fragen

5. Exclamatory or emphatic use B2 informal

   Used in exclamations or rhetorical questions to emphasize the surprising extent of speed, rapidity, or urgency.

   • How fast a time you ran that mile!
   • How fast do you expect me to work?
   • How fast the world is changing!

   🇩🇪Ausrufender oder verstärkender Gebrauch