The Forgetting Curve

In the 1880s, a German psychologist named Hermann Ebbinghaus did an unusual experiment on himself. He learned long lists of meaningless words, such as made-up syllables, and then he tested how many he could remember after twenty minutes, one hour, one day and one week. He wrote down his results carefully for many months.

His discovery became famous as the forgetting curve. When you draw it on a graph, the line goes down very fast at the beginning and then becomes slower. In other words, we forget the largest part of new information in the first hours and days. After that, the memory that remains is more stable. The exact numbers change from person to person and from subject to subject, but the shape of the curve is a useful picture to keep in your head.

What does this mean for a language learner? First, forgetting is normal. If you forget the words from yesterday's lesson, it does not mean that you are weak at languages. Your brain is working exactly as expected. Second, the first review is the most valuable. A short review soon after a lesson, for example the same evening or the next morning, catches the memory before it falls too far.

Ebbinghaus also found that each repetition changes the curve. After a review, the line goes down more slowly. After a few reviews, the memory can stay for weeks or months. This is the idea behind spaced repetition: review, wait longer, review again.

Here is a practical routine. Learn new words in the morning. Say them again in the evening. Check them the next day, then after three days, and after one week. You do not need hours. A few minutes each time is enough.

The forgetting curve is not bad news. It is a map. It tells you when to act, and acting early is much easier than starting again from zero.