Indirect Questions 

Indirect questions are subordinate clauses. The verb takes the last position at the end of the subordinate clause.

There are two kinds of indirect questions:
1. The indirect questions replaces a so-called W-question (warum, wie, wann, wo etc.).
The indirect questions starts with the interrogative pronoun (warum, wie, wann, wo etc.).
Direct question Wie heißt sie?
Indirect question Philipp möchte wissen, wie sie heißt.
2. The indirect question replaces a question which can only be answered with "yes" or "no".
The indirect questions starts with "ob" (whether).
Direct question Wird morgen ein heißer Tag?
Indirect question Philipp möchte wissen, ob morgen ein heißer Tag wird.