"accomplishment"和"achievement"在某些情况下都可数，但在其他情况下则不可数，这取决于它们的用法。

1. 当"accomplishment"和"achievement"指具体的、独立的事物或事件时，它们是可数名词。例如：
- "I have two major accomplishments this year: finishing my thesis and learning to play the piano."
- "She celebrated her latest achievement, winning the national championship."

2. 当它们表示一种状态或抽象的概念时，它们通常是不可数的。例如：
- "His accomplishment in the field of science is remarkable."
- "The feeling of achieving something after hard work is priceless."

因此，使用时需根据上下文判断其是否可数。