Breakdown of Как называется эта улица?
улица
street
этот
this [f: эта, n: это]
как
how
называться
to be called, to be named (of things)
Questions & Answers about Как называется эта улица?
Why do we use Как instead of Что to ask 'What is this street called?'
In Russian, the standard way to ask for a name uses как (how). Literally, you are asking 'How does this street call itself?'. If you used что (what), it would sound absurd, as if you were asking what the street is physically saying out loud.
This lesson is about verbs taking the Instrumental case, like называть. How does that apply to the reflexive называться used here?
The active verb называть strictly requires the Accusative for the object and the Instrumental for the name. The reflexive называться turns the object into the subject (in the Nominative case, like эта улица). When you answer this question, you can use the Instrumental case for the name, such as Она называется Тверской, though the Nominative is also very common for proper nouns.
Is it grammatically incorrect to say Как эта улица называется? with the subject before the verb?
It is not incorrect, but the word order in the example is much more natural. In Russian questions, the specific subject being asked about is usually placed at the end of the sentence to emphasize it.