The words "welcher", "welche" and "welches" can be used to begin a question. You can use them to ask about someone or something in particular or to choose something from a certain contingent.
Examples:
Ich suche eine Frau. – Welche Frau?
Welche Farbe hatten ihre Schuhe? – Weiß.
The question words reflect the number, gender and case of the noun they modify:
| Masculine | Feminine | Neuter | ||||
| Nominative | welcher | welche | welches | |||
| Accusative | welchen | welche | welches | |||
| Dative | welchem | welcher | welchem | |||
| Genitive | welches | welcher | welches |