The Interrogativartikel is a type of article in German. An Interrogativartikel cannot stand alone; it must be accompanied by a noun. They are commonly used in questions. In today's article we will learn about this type of article. 

1. Interrogativartikel welch-

• Welch- requires the definite article and is usually used in questions of choice. The person being asked knows the options, or the options have been mentioned before. 

Welches Auto gehört dir? 

(Which car is yours?)

→ welches Auto is the subject → Nominativ

• Welch- also often appears after prepositions: 

An welcher Uni studierst du? - Ich studiere an der Leipzig Uni. 

(Which university do you study at? - I study at Leipzig University.) 

→ an + Dativ → an welcher Uni

• The answer usually uses the Demontrativartikel or the definite article der/die/das/….. 

Welches Auto gehört dir? - Dieses Auto. 

(Which car is yours? - This car.) 

Welches Auto gehört dir? - Der Porsche. 

(Which car is yours? - The Porsche.) 

• Declension of welch- 

2. Interrogativ was für ein-

• Was für ein- requires the indefinite article. A question with was für ein- is an open, general question; the options are numerous and unlimited. 

Was für eine Jacke suchen Sie? - Einen leichte Windjacke. 

(What kind of jacket are you looking for? - A light windbreaker.)

→ was für eine Jacke is the object → Akkusativ

• Declension of was für ein-