suddenly和All of sudden 的區別如下：
suddenly著重於動作在沒有預兆而突然發生，也就是“意料之外地”，例句：
Family values are suddenly the name of the game. 家庭價值觀突然變得重要起來。
He mays uddenly take a dislike to foods that he's previously enjoyed. 對以前愛吃的食物，他興許突然就沒了胃口。
all of sudden著重於動作的迅猛程度，也就是“剎那之間”、“壹眨樣的功夫”或“千鈞壹發”，例句：
We had to stop all of sudden as well. 我們同樣不得不突然停下來.
All of sudden he was attacked by a robber. 突然他遭到壹個強盜的襲擊.?
all of sudden的用法常放在句首，suddenly的用法比all of sudden廣闊。
suddenly：I suddenly remembered that I hadn't locked the door.
我突然記起我沒有鎖門.
all of sudden：All of sudden we heard a loud explosion that shook the building.
突然之間我們聽到壹聲巨大的爆炸聲沖擊著那個建築物。