I am writing to answer your question and inform you about earthquakes and volcanoes. Most earthquakes are occurring near the edges of the continents like North America , South America, east coast of Asia and Australia and all of the earthquakes happen in the same place or they happen in bunches.
Yes there is a way to determine what parts of the world are prone to the earthquakes. I found that out by using a map to plot down where all the earthquakes are happening. We saw a pattern were the earthquakes are happening.
Yes there is a relationship between earthquakes and volcanoes because earthquakes and volcanoes mostly happen in the same places ,and earthquakes make volcanoes erupt . It all depends if they are near each other.
We have earthquakes because the earth crust is broken into pieces called, and the plates are moving ,For an example they over lap ,bump in to each ,or they can move away from each other when they do this that is how earthquakes start to happen.