Learn Spanish (Latin America): La radio está en el dormitorio.

We use está (a form of the verb estar) because we are talking about the location of a specific thing (the radio, la radio). If we wanted to say 'There is a radio in the bedroom,' we would use the unspecific word hay instead: Hay una radio en el dormitorio.

Why is it la radio? Doesn't the -o ending make it masculine?

Normally, words ending in -o are masculine, but radio is a famous exception! It is actually short for la radiodifusión (broadcasting), which is feminine. Because of this history, it keeps the feminine word for 'the', making it la radio.

Does en always mean 'in'?

En is a very useful and flexible word that can mean 'in', 'on', or 'at' depending on the context. Here it means 'in', but if the radio were sitting on a table, you would still use en: La radio está en la mesa (The radio is on the table).

Why does está have an accent mark over the a?

The accent mark changes the word's meaning and pronunciation. Está (with the accent) means 'is'. If you take the accent away, it becomes esta, which means 'this' (like in esta radio - this radio).