We can ask questions with the verb to be by placing the question particle mİ with the personal ending after the noun or adjective. The negative counterpart of the question is made by inserting the word değil before the question particle.

	Singular	Plural
First person	[değil] mİyİm	[değil] mİyİz
Second person	[değil] mİsİn	[değil] mİsİnİz
Third person	[değil] mİ	[değil](lEr) mİ

Note that in the third person plural, the plural suffix lEr comes behind değil or behind the noun or adjective, and not behind the question particle. The plural suffix is only used if the subjects are human, and even then it is optional.

You can see some example sentences below:

Am I a child?	(Ben) (bir) çocuk muyum?
Aren't you rich?	(Sen) zengin değil misin?
Is it a rose?	O bir gül mü?
Aren't we poor?	(Biz) fakir değil miyiz?
Are you ok?	(Siz) iyi misiniz?
Are they crazy?	Onlar deli(ler) mi?
Are they crazy?	Deliler mi?
Aren't they expensive?	(Onlar) pahalı değil(ler) mi?

Usages of deli