Learn Spanish (Spain): ¿Hay un armario en la habitación?

In Spanish, you do not need to change the word order to turn a statement into a question like we do in English. The word hay means "there is", but when you put it inside question marks and raise your voice at the end, it automatically means "is there?".

If I wanted to ask "Are there wardrobes in the room?", would "hay" change?

No, hay stays exactly the same. It is a very handy word because it means both "there is" and "there are" (as well as "is there" and "are there"). You would just ask ¿Hay armarios en la habitación?.

How do I know to use "la" with "habitación"?

The word habitación ends in -ción. In Spanish, almost every single noun that ends in -ción is feminine. That is a very helpful rule to remember because it means they will always use the feminine word for "the", which is la.

I have seen "en" used to mean "on". Why does it mean "in" here?

The Spanish word en is very flexible and can mean "in", "on", or "at" depending on the context. You just have to look at what makes the most sense. Since an armario (wardrobe) goes inside a room, "in" is the natural translation here.