| 前缀 | 核心含义 | 典型例词 |
|---|---|---|
| de | down（下降）/away（离开、偏离） | decrease、descend、derail、deject |
| e/ex | out（出来） | erupt、eject |
| trans | change（改变）/cross（穿过、跨过） | transform、transgress、transaction |
| sub | under（在… 之下）/after（在… 之后，表次要） | subway、submarine、substitute、subtitle |
| re | back（回）/again（再）/against（反对），back 为最常用 | reject、react |
| pro | forward（向前） | project、subject |
| inter | between（在… 之间） | interact |
| in | into（进入）/ 否定（形容词前） | inject、inactive |
词根 1：ject（含义：扔，动作特点：迅速、猛烈；无后缀时为动词）
- inject：in+ject，表 “猛烈地进入”，含义为注射，近义 infuse，例句：He tried to inject confidence into his brother.
- eject：e+ject，表 “猛烈地扔出去”，含义为弹出、驱逐，近义 deport，例句：The pilot ejected when his plane caught fire.
- deject：de+ject，表 “把精气神压下去”，含义为使沮丧，程度较深，近义 dismay，例句：The bad news dejected me.
- reject：re+ject，表 “扔回来”，含义为拒绝，近义 refuse，例句：The baby rejected medicine.
- project：pro+ject，表 “向前扔”，①动词投射，近义 cast，例句：The machine projects motion pictures on the screen.；②名词项目 / 计划，近义 program，例句：Students complete their projects at their own pace.
- subject：sub+ject，表 “扔到下面”，①动词使服从、使遭受，重读在第二个音节，例句：He has subjected her to four years of beatings and abuse.；②名词学科、科目，为常用含义，例句：Chemistry was my favorite subject in high school.
词根 2：act（含义：行为、动作、表演；本身可作单词使用）
配套讲解了 or（表人，名词后缀）、ess（表女性，名词后缀）、ive（形容词后缀）、ate（动词后缀）、ion（名词后缀） 等后缀，衍生词如下：
- actor：act+or，含义为男演员，例句：You have to be a very good actor to play that part.
- actress：act+ess，含义为女演员，例句：She’ll make good actress if she gets a right training.
- active：act+ive，含义为活跃的、积极的，近义 vigorous，例句：We’ll stay active during cold winter month by skiing and skating.
- inactive：in+active，in 表否定，含义为不活跃的、静止的，例句：It’s easiest to catch snakes early in the morning while they’re still cold and inactive.
- activate：act+ivate，含义为使活动、使启动，近义 trigger，例句：The bomb was activated by remote control.
- interact：inter+act，含义为相互作用、互动，近义 communicate，例句：Chemicals interact to produce smoke./Teachers have limited amount of time to interact with each child.
- react：re+act，re 表 back，含义为回应、反应，例句：The firefighters reacted quickly when they heard the alarm.
- reaction：react+ion，名词，含义为反应、回应，例句：He had an allergic reaction to peanuts./The reaction to the news was positive.
- transaction：trans+act+ion，trans 表 change，含义为交易，表 “从一人手中转到另一人手中的行为”。