A02
core
Scene core
Participant roles
Actor / Source
Who or what starts the event?
basic
Subject
Agent
Causer
含义
The participant that acts, causes, initiates, controls, or is presented as the source of an event.
如何识别
Ask who is doing, causing, or starting the event.
示例
单词
I|Peter|the dog|the machine|the wind
短语
the teacher explains|the wind opens
句子
The dog bit the postman.
Visual guide
Basic shape
ACTOR / SOURCE who starts the event? [the dog] -> bit -> postman [the wind] -> opens [the teacher] -> explains = doer/causer/source
Compare shape
Actor clues may differ order: [dog] bit postman case: [dog-NOM/ERG] agreement: dog -> verb pronoun form: I / me topic: [dog-TOP] voice: by [dog] role = event starter
语言视角
用母语深入讲解
中文
显性程度
strong
重要程度
The actor is commonly placed before the verb, but Mandarin can omit it when obvious and can also front a topic before the comment.
她打开了门。
tā dǎkāi le mén = she opened the door
在所学语言中
英语
显性程度
strong
学习难度
在基础英语句子中，动作的发起者通常放在动词前面；它也会影响动词形式，例如 she opens 中的 -s。
She opened the door.
She = 行动者/来源（打开门的人）
常见易错点
来自语序较自由语言的学习者，可能把行动者随意移到别的位置，或省略英语通常需要的主语。
Same block, different coding
Both languages use this block strongly, but they signal it differently. Focus on form changes, not only meaning.