Question

descend on

Accepted Answer

   ! Descend upon is more formal than descend onand is mostly used in writing.
  1. descend on/upon sb/sth if a group of people descend on a person or place, they all arrive suddenly, often without being invited:
   ▪ If friends suddenly descend on you at the weekend, you just have to hope you have something in the freezer.
   ▪ Thousands of football fans descended on the town.
  2. descend on/upon sb/sth if a type of weather, or silence, calm etc descends on a person or place, it seems to start very suddenly:
   ▪ A heavy fog suddenly descended on us, and we realized that we were lost.
   ▪ It was early evening, and calm had descended upon the river.
  3. descend on/upon sb if a sad feeling descends on you, you suddenly start to feel it:
   ▪ A black depression descended on her at the thought of the future.

Descended Descend Suddenly On/Upon Sb/Sth If Person Place Calm Start