изненадан in inglese:

The sudden increase of ultraviolet rays made the researchers believe in the existence of ozone holes.

The sudden increase of cars is causing a large number of traffic accidents every day.

Sudden decrease in appetite is sometimes a sign of illness.

a sudden rise

As I returned from school yesterday, I was caught in a sudden shower.

However, maybe from the sudden change in pressure when you put them, having your ears pop is a problem.

Losing his balance from a sudden gust of wind, the tightrope walker fell to his death.

What Alice, waiting for a reply, was faced with was a sudden howl. It was a resounding noise, sharp as to burst her ear drums, loud as to reach unto the heavens.

When the teacher called on me all of a sudden I got confused and kept stumbling as I spoke.

He was to have dined with us, but he became seriously sick all of a sudden.

There are no car lights to make it softer or less sudden; there are no mothers voices calling for their children to come in now.

Numerous violent and sudden casualties among C++ developers are caused by segmentation faults every year.

Nothing can change the look of a city so dramatically as the sudden appearance of a block of offices which towers above all the surrounding buildings.

There are many theories about the sudden extinction of the dinosaurs, but the real cause still remains anyone's guess.

Why are you telling me about hippos all of the sudden? I don't see the connection between that and your twelve red goldfishes.