Learn Russian: Это город? Нет, это не город.

Нет is the direct answer meaning 'No' (the opposite of 'Yes'). не means 'not' and is used to make the rest of the sentence negative. You will very often see them used together like this when answering a yes/no question.

Why is не placed exactly where it is in это не город?

In Russian, to say that something is not a certain thing, you place не directly before the word you are negating. Since we are saying it is not a city, не goes right in front of город.

Where are the words for 'is' and 'a' in this sentence?

Russian does not use the verb 'to be' (am, is, are) in the present tense, and it does not have articles like 'a', 'an', or 'the'. So, Это город naturally translates to 'This [is a] city'.

How do you show that Это город? is a question when the words are in the same order as a statement?

Unlike English, which often swaps the word order (changing 'This is' to 'Is this'), Russian keeps the exact same word order. You just add a question mark in writing, and raise your voice on the most important word (город) when speaking.