X wa Y desu ka? Sentence Pattern
A simple and easy to use sentence pattern, but yet very useful is the X wa Y desu ka? sentence pattern. X is the subject of the sentence, and what you are asking the question about. Y can be just about any question word, such as doko (where), itsu (when), etc. So for example, if you want to ask where the toilet is, you can say otoire wa doko desu ka? Or if you want to ask how much something costs, you can say kore wa ikura desu ka?