Most things in life happen “suddenly.” They may not happen quickly or unexpectedly. In fact, they might be very predictable, but when they happen, they happen suddenly.
Using the words “suddenly” or “sudden” is therefore most often redundant, serving primarily to identify the writer as a rank amateur. Stephen King makes this point with great good humor in his book “On Writing.”
Let’s take a simple example:
“Suddenly, the telephone rang.”
Telephones always ring suddenly, even when you are expecting the call.
I see this all the time in undergraduate college admissions essays. In a misguided attempt to color a rather commonplace situation with a sense of sweaty urgency, applicants combine suddenly ringing telephones, especially very early in the morning, with squealing mother’s urging them out of bed to answer the call of destiny.
This will neither attract nor retain the reader’s attention. If anything, it may persuade them to read no further.
Avoid “suddenly” like the plague.