Actor / Source
Subject
Agent
Causer
Who or what starts the event?
core
basic
Scene core
意味
The participant that acts, causes, initiates, controls, or is presented as the source of an event.
見分け方
Ask who is doing, causing, or starting the event.
例
単語
I|Peter|the dog|the machine|the wind
フレーズ
the teacher explains|the wind opens
文
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
言語別ビュー
母語では
Japanese
表れ方
strong
重要度
The actor is often marked by が or introduced as topic with は, but it can be omitted when clear.
犬が走った。
The dog ran.
学習中の言語では
Arabic (Modern Standard)
表れ方
strong
難易度
Actors are often nominative and reflected in verb agreement; explicit subjects can be omitted when the verb is enough.
كتب الطالب الدرس.
The student wrote the lesson.
よくあるつまずき
Learners may rely only on word order and miss agreement or nominative marking.
Same block, different coding
Both languages use this block strongly, but they signal it differently. Focus on form changes, not only meaning.