Final answer:
Students finding it easier to brush up on a foreign language they learned before when going to graduate school illustrates the concept of relearning.
Step-by-step explanation:
The fact that students find it easier to brush up on a foreign language they have learned before when they go to graduate school illustrates the concept of relearning. Relearning is the process of learning information that you have previously learned.
When you learn a foreign language for the first time, you are acquiring new knowledge and skills. However, if you have learned the language before, even if it has been a while since you last used it, you have already built a foundation. This foundation makes it easier to relearn the language.
For example, someone who studied Spanish in high school and then years later decides to brush up on their language skills for graduate school will find it easier to relearn Spanish compared to someone who is completely new to the language.