He opened the door. Light suddenly filled the room revealing the embarrassed couple embracing on the sofa.
She was driving down the street, but then suddenly, out of nowhere, another car ran a stop light and T-boned her.
Please be careful when crossing the stream. A stream of light suddenly lit up the whole room.
Suddenly, my nose wrinkled in a convulsive reaction.
Suddenly David was stricken by the stupidity of what he'd done.
No, but you can make a sentence with the word suddenly. Suddenly it started to rain.
The light is so bright in the morning.
Suddenly.
Suddenly the boy whacked me on the head.
Suddenly, The door slamed closed
Suddenly, The door slamed closed
ex) Someone is reinventing the light balb.
Using commas with introductory adverbs is a stylistic consideration. Using a comma in this situation is never incorrect, but many writers have recently started omitting the comma. You could also try moving the adverb around in the sentence, expunging this problem completely: instead of saying "Suddenly, the filled cup fell off the table," you could write "The filled cup suddenly fell off the table," or "The filled cup fell off the table suddenly."