Yes/no questions can be answered with either "yes" or "no".
Do you remember that in a simple declarative sentence, the verb comes second?
Well, with yes/no questions, you switch the position: The verb comes first.
| Declarative sentence: | Julia | zahlt | meine Rechnung. |
| Yes/no question: | Zahlt | Julia | meine Rechnung? |
| Declarative sentence: | Julia | ist | meine Freundin. |
| Yes/no question: | Ist | Julia | meine Freundin? |
| Declarative sentence: | Julia | hat | Ihr Geld. |
| Yes/no question: | Hat | Julia | Ihr Geld? |
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In colloquial speech, yes/no questions can also be formed using the same word sequence as in the declarative sentence by simply adding a question mark and raising your voice at the end.
Example:
Sie zahlt Ihre Rechnung?