Complex sentence: Because of Josef Stalin's fear of restoration of capitalism in USSR, he abandoned NEP and started prosecuting private entrepreneurs, so in 1929 Yuri's grandfather had to sell his equipment and bury a tile machine.
Split into simpler sentences: Because of Josef Stalin's fear of restoration of capitalism in USSR, he abandoned NEP and started prosecuting private entrepreneurs. In 1929 Yuri's grandfather had to sell his equipment and bury a tile machine.