How do you use the expression 'est-ce que' to ask a question in French?

'Est-ce que' is a very versatile group of words, centered around the word 'est', from the verbe 'etre', meaning 'to be'.

'Est-ce que' can be translated into various meanings, depending on the context. 

To ask where a location is, for instance, you may want to start the sentence with 'Où est-ce que...?' meaning 'Where is...?'. For example, 'Excusez-moi, où est-ce que se trouve l'eglise?', translating into 'Excuse me, where is the church?'. 

You may also use 'est-ce que' when asking about timing, with the expression 'à quelle heure' ('at what time') or 'quand' ('when'): 'Quand est-ce que cette ceremonie commence?' = 'When does this ceremony start?'. 

There are many other ways of using this group of words, another one being the word 'Comment' ('Comment est-ce que..?'), meaning 'How' ('How can..?') and it is very important to grasp this in order to ask questions in French.