The elative is one of the six paikallissijat or location cases. This case is usually used in the same instances when from or out of would be used in English.
 
 

When is the elative used?

• To talk about something leaving the inside of a particular place:

 
• Eilen kun tulin kirkosta, huomasin, että ovikelloni oli mennyt rikki.  Yesterday when I came (back) from church, I noticed that my doorbell had broke.
• Hän matkusti Moskovasta Helsinkiin. He traveled from Moscow to Helsinki.
• Mistä tulit äskettäin? Where did you just come from?
• Kun astut taloon Suomessa, on pakko ottaa kengät jalasta ja jättää ne eteiseen.  In Finland, when you come inside, you must take off your shoes and leave them in the foyer/hallway. (NB. Finns do not wear their shoes in the house and they always scrape them outside and remove them immediately upon entering a house, so remember to bring decent socks with you!  Some Finns also have shoes that are specifically for use at work, so they don't track mud and snow inside.  Also when you go play sports, you have to have a set of shoes that is solely for indoors use so as not to scratch up the floors!)
• Otin avaimet laukustani. I took my keys out of my bag. (NB. Finnish uses the possessive markers here less than English does, so even though there is no possessive marker on avaimet, it could also mean my keys.)
• Poimin avaimeni maasta. I grabbed my keys off the ground. (NB. Here I would use the possessive marker to indicate that they are mine since the following word doesn't belong to me, like laukka did in the previous sentence.)

 
• Remember that some towns that take the adessive:
 
• Hän matkusti Imatralta Helsinkiin. He traveled from Imatra to Helsinki.

 
For more information on which case the towns take, please see the KKTK site.
 
• With time expressions, it says how long something was done.  Used when the English expression has from ~  to in it:
 
• Kello kolmesta viiteen luin tämän päivän sanomalehteä.  I read today's newspaper from three to five o'clock.

• Words that require the elative