As in English you can start a question with a question word. Here are some common question words.

 Try guessing the meaning before displaying the answer
Was...?
Wann...?
Wo...?
Wer...?
Wohin...?
Wie viel...?
Was...? What...?
Wann...? When...?
Wo...? Where...?
Wer...? Who...?
Wohin...? Where to...?
Wie viel...? How much...?

As in English, the question word comes at the start of the sentence, followed by the verb.

Was sind Sie von Beruf?                                                       What's your job?
Was ist das?                                                                          What's that?
Wo wohnen Sie?                                                                    Where do you live?
Wohin, bitte?                                                                          Where to, please?

Sometimes when asking a question, there is no question word. You can simply change the word order of the sentence, just as you do in English.

 Try asking the questions before displaying them

Das ist ein Taxi                                                                         That is a taxi
Das ist der Ku'damm                                                                That's the Ku'damm
Wir sind da                                                                               We're there