How can we avoid forgetting what we have learned? Now I would like to give you four suggestions. Then I'll give you a bit explanation on each of them.
Suggestions
First, we need to learn words repeatedly with increasing intervals between learning sessions. Here, the most important term “increasing” intervals, 就是说这个间隔的时间要恰当。I will explain it later. （按照适当的时间间隔来温习新学的单词。）
The second we should have the words. We have the words we want to learn with us whenever we go. So if we want to learn these words, we should have these words with us. So we can make full use of our time learning these words. （时时刻刻，利用边边角角的时间去复习生词。）
The third is set aside a regular time for vocabulary learning. （留出专门的时间用于单词学习。）
The last one, spend more time on the words you find difficult. All these suggestions are not new to you, I guess. But you might find something new later. （对疑难词汇进行重点攻关。）
Suggestion One
Ok. The first one. Increasing intervals. Now research in psychology shows that we do not forget things gradually. You see a psychologist did research. Most of our forgetting occurs within 20 minutes after we have first learned something. More is forgotten with one hour. Still more within 8 hours. After 8 hours, the rate of forgetting stays surprisingly steady. You see, we do not forget things gradually, bit by bit. Bit by bit. It’s not the case. So we forget more in the first 8 hours. （心理学研究者做过一个测试：我们最易遗忘的时间段是我们接触新知识后的头20分钟。之后的1个小时我们又会忘记一些，然后8小时内又忘记一些。过了8小时，我们的遗忘速度就会趋于稳定。也就是说，遗忘是一点一点发生的，前8个小时忘得最快。）
So what should we do? What should we do? And actually, I will suggest you should do revision everyday when you first learn the new words. And then you may spend some time review the words once in a week. Then later on, once in a month. So increasing intervals, I mean you learn frequently at the very beginning. Then gradually, you can delay a little bit. The interval is longer and longer. But still you have to review them. Now this is the first suggestion. Increasing intervals. （针对这种遗忘规律，文教授提议：接触新单词之后，起初反复记忆，然后逐步拉长复习的时间间隔。）
Suggestion Two
The second suggestion is make full use of “dead” time. Dead. Why I use the word in the quotation marks? The “dead” time. Now when I say “dead” time, I mean those time is not useful any more. You know, when you are walking on the way, when you are in a bus, when you are, let me see, when you are lying on the bed before you sleep. All these time can’t be used for very important things. But you can make full use of “dead” time to learn some words. And you can use your vocabulary notebook, you can use your electronic dictionary, just very small, learn few words every day. Every day. Try to use this kind of time learning words, eventually your vocabulary will be expanding quickly. （利用一切可以利用的时间。行走中，公车上，睡觉前......这些相对来说不能做重要事情的时间段，你就可以分心用来背单词。一天记几个，积少成多，你就会发现自己的单词量突飞猛进。）
You do not need whole day learning vocabulary. Don’t do in this way. And you may use just small amount of time every day. Let’s say, in the morning, 20 minutes, in the afternoon, 20 minutes, in the evening, 20 minutes. Suppose you want to spend one hour, you’d better separate it into three sessions, 20 minutes each. Suppose you want to learn vocabulary half an hour a day, maybe you’d better divide them into two sections, 15 minutes a section. Don’t put them together. （不要成天成宿地背单词，花费大段大段的时间记单词会降低学习效率。如果你每天计划利用1个小时背单词，那么就把这1个小时拆分成早、中、晚三部分，每次安排20分钟背单词。）
And then every day you learn a little bit. Then eventually, at the end of the week, you have spent about half an hour putting all these words together, go over them. Later I will mention, don’t go over all the words. You have to select some of them to focus your attention. Now electronic dictionary also is a good way to learn words, because there is a sort of file for you to put those difficult words, right? Just put in your pocket. You can learn them anytime you can do it. （一天记一点，周末抽出半小时有侧重点地巩固一周的学习成果。可以利用电子辞典的归档功能筛选出疑难词汇，然后放在身边随时翻阅。）
Suggestion Three
And suggestion 3. And my suggestion is daily revision. Ten minutes a day. Weekly revision. One hour a week. Monthly revision. One hour a month. So that intervals, the first is a week, the next is a month. （除了学习新单词，还要注意复习这些单词。一天十分钟，一周一小时，一个月一小时——以这种频率不断温习这些单词，必能收到良好的效果。）
Suggestion Four
And the final suggestion is to spend more time on the words you find difficult. I found some students would like to go down a list from the first to the last, trying to memorize each one. You’ve got a vocabulary list. From first to the end. From the first to the end. Every day, they follow the same pattern. （重点记忆自己认为比较难的单词。不要年复一年地拿着词汇大纲从头看到尾。）
Now there are two problems for this kind of practice. The words at the top of the list tend to be remembered better. Then the words further down. Right? Time is wasted on the words that have been learned. What can be done? I’ll give you an example. This example is given by a researcher. （不要把复习单词的时间浪费在已经记住的单词上面。）
Now I give you the footnote there. Suppose you have got these new words in one text: rewarding, frustrating, junior, positive, senior, opportunity, online, technology, participate, virtual, virtual classroom. Ok. You’ve got so many words. Suppose all these words you are asked to learn. And you remember them at the end of the day. Let’s say. In the evening, you remember them. And tomorrow you go over them again. You found you forgot many of them. You only remember few of them. （举例来说，粗体部分是你要学习的新单词。头天你学习完毕，第二天复习的时候你发现只记住了其中的几个，却忘记了大多数。）
So what should you do tomorrow? Should you go over them from the beginning to the end again? No. So this is the suggestion. If you, suppose you remember these words, junior, positive, senior, online, virtual, if you remember these words, put these words in another column. And then you only focus on, next day, you only focus your attention on the remaining five words. Don’t go over ten words again. Focus on five words. Ok. （那么，你不必再复习已经掌握的部分【比如说粗体标出的单词】，你只需复习你没有记住的另5个单词。）
So you classify these words into three types. If you are familiar with them, you review them once. And then you review them once in a week. If you review them once in a week, no problem at all. You put them in a monthly column. So you review them once for a month. （你可以做一张三列的表，三列的标题分别为：daily， weekly 和monthly。起初，所有的单词都放在daily这列，第二天复习的时候，记住的单词就可以挪到weekly这列，如果周复习的时候你仍然记得它们，就可以将之挪到monthly这列。）
But for those words, if you can not remember daily, you have to review them again and again. But the words become fewer and fewer. Not so many. So you can focus your attention on those things which are very difficult for you. This work makes learning more efficient. （如果放在daily栏中的单词始终记不住，那么就让它们始终呆在daily栏中，天天强化记忆。坚持使用这种方法，你会始终关注你最需要关注的单词，提高效率不说，你也会发现daily栏中的单词最终全部挪到monthly栏中，并永远刻在你的脑海中，一辈子无法遗忘。）
