一、often
adv.經常;常常;時常;再三
例句
1、This resulted in overpriced and often inferior products
這就導致了標價過高而往往質量低劣的產品的.出現。
2、People often have incorrect information about food.
人們對食物經常會有不正確的認識。
3、She was often downright rude to him.
她常對他十分粗魯。
二、usually
adv.通常，經常，平常，慣常地;一直，向來;
例句
1、This year hotels that usually are jammed had vacancies all summer.
今年，那些通常爆滿的旅店整個夏天都有空客房。
2、Finance is usually the biggest problem for students.
經濟問題通常是學生最大的問題。
3、This condition usually clears up with regular shampooing.
這種情形通常多用香波洗洗頭即可消除。