Closed questions always start with a verb, the finite verb to more precise. While in English, we usually need an auxiliary verb (to do) to form a proper closed question, in Dutch we can do without. All it requires is inversion of the [finite form](#/lesson/WordOrder.04) and a question mark at the end of the sentence:
Jullie staan meestal vroeg op | You usually get up early
Staan jullie meestal vroeg op? | Do you usually get up early?
As you can see, the question is almost identical to the affirmative phrase. The only change is from jullie staan (affirmative) to staan jullie (question).
Arjan is niet op haar verjaardag gekomen | Arjan has not visited her for her birthday
Is Arjan niet op haar verjaardag gekomen? | Has Arjan not visited her for her birthday?
The above sentence is both a question and a negation. You can see that _niet_ is situated between the middle and the right part: _op haar verjaardag_ is a [prepositional object](#/lesson/WordOrder.35), which sits at the beginning of the right part.
Er waren geen getuigen van het ongeval | There were no witnesses of the accident
Waren er geen getuigen van het ongeval? | Were there no witnesses of the accident?
Because the subject is non-specific (geen is an indefinite pronoun), we add the little word _er_. See also [extra er at the beginning of a sentence](#/lesson/WordOrder.40). If we turn this type of sentence into a question, it is _er_ that switches places with the verb, not the subject (geen getuigen).