Causative Form使役形
The causative form (使役形) means "make someone do" or "let someone do." The distinction between coercion and permission depends on context and particles. For godan verbs, shift to the あ-row and add -せる. For ichidan verbs, drop -ru and add -させる. This is one of the key intermediate forms that unlocks complex interpersonal expressions.
The causative form (使役形) means "make someone do" or "let someone do." The distinction between coercion and permission depends on context and particles. For godan verbs, shift to the あ-row and add -せる. For ichidan verbs, drop -ru and add -させる. This is one of the key intermediate forms that unlocks complex interpersonal expressions.
How to form the causative
The causative adds -(s)aseru to the verb stem.
Godan: あ-row + せる
Change the final kana to the あ-row and add せる: 行く→行かせる (ikaseru), 書く→書かせる (kakaseru), 読む→読ませる (yomaseru), 話す→話させる (hanasaseru), 待つ→待たせる (mataseru), 飲む→飲ませる (nomaseru). For う-ending verbs: 買う→買わせる (kawaseru).
Ichidan: stem + させる
Drop -ru and add -させる: 食べる→食べさせる (tabesaseru), 見る→見させる (misaseru), 起きる→起きさせる (okisaseru), 寝る→寝させる (nesaseru).
Irregular
する→させる (saseru). 来る→来させる (kosaseru). させる (from する) is extremely common and used as a general "make/have someone do" construction.
"Make" vs "let" — the particle difference
The same causative form can mean "make" (coerce) or "let" (permit). The distinction comes from particles and context.
を — coercion / "make"
When the caused person takes を, the nuance is forcing or making someone do something: 先生は学生を立たせた (The teacher made the students stand). 母は子供を野菜を食べさせた becomes awkward with double を — see particle note below.
に — permission / "let"
When the caused person takes に, the nuance is allowing or letting: 母は子供にゲームをさせた (The mother let the child play games). 先生は学生に自由に発表させた (The teacher let the students present freely).
Double を problem
When the original verb already takes an object with を, you can’t have two を in one clause. In this case, the caused person takes に: ✗ 子供を野菜を食べさせた → ✓ 子供に野菜を食べさせた. The object keeps を, and the person being made/let do the action takes に.
～させてください — "please let me"
The causative + て form creates one of the most useful polite expressions: させてください (please let me do). やらせてください (Please let me do it), 考えさせてください (Please let me think about it), 説明させていただきます (Allow me to explain — humble/business). This is how you ask for permission in formal Japanese, much more natural than the plain "may I?"
Shortened causative (godan only)
In casual speech, godan causative forms are often shortened: 行かせる→行かす (ikasu), 読ませる→読ます (yomasu), 飲ませる→飲ます (nomasu). This shortened form is common in western dialects (Kansai) and increasingly in casual standard Japanese. Ichidan verbs and irregulars do not shorten this way.
Cultural nuance
The causative form inherently implies a power relationship. Using it inappropriately can sound presumptuous or controlling. 部長が社員を残業させた (The boss made employees work overtime) is natural — the boss has authority. But saying 友達を行かせた (I made my friend go) about an equal relationship sounds controlling unless context justifies it. For equals, Japanese speakers prefer ～てもらう (receiving a favor) instead.
Causative form conjugation
| Verb | Group | Causative | Causative negative | Causative polite |
|---|---|---|---|---|
| 行く | Godan | 行かせる | 行かせない | 行かせます |
| 書く | Godan | 書かせる | 書かせない | 書かせます |
| 読む | Godan | 読ませる | 読ませない | 読ませます |
| 飲む | Godan | 飲ませる | 飲ませない | 飲ませます |
| 待つ | Godan | 待たせる | 待たせない | 待たせます |
| 食べる | Ichidan | 食べさせる | 食べさせない | 食べさせます |
| 見る | Ichidan | 見させる | 見させない | 見させます |
| 起きる | Ichidan | 起きさせる | 起きさせない | 起きさせます |
| する | Irreg. | させる | させない | させます |
| 来る | Irreg. | 来させる (kosaseru) | 来させない | 来させます |
Example sentences
先生は学生にレポートを書かせた。
Sensei wa gakusei ni repooto o kakaseta.
The teacher had the students write a report.
に marks the doer — assignment context
母は私に好きな服を選ばせてくれた。
Haha wa watashi ni suki na fuku o erasasete kureta.
My mother let me choose the clothes I liked.
させてくれる = let (with kindness)
部長が新人を走らせている。
Buchou ga shinjin o hashirasete iru.
The manager is making the newcomer run.
を marks the doer — coercion nuance
すみません、少し考えさせてください。
Sumimasen, sukoshi kangaesasete kudasai.
Excuse me, please let me think about it.
させてください — polite permission request
子供にピアノを習わせている。
Kodomo ni piano o narawasete iru.
I’m having my child take piano lessons.
Parent making decisions for child
彼を待たせてしまった。
Kare o matasete shimatta.
I ended up making him wait.
～てしまう adds regret to causative
Common mistakes
子供を牛乳を飲ませた (double を)
子供に牛乳を飲ませた
Japanese does not allow two を in one clause. When the verb already takes an object (牛乳を飲む), the caused person must take に: 子供に牛乳を飲ませた.
友達を来させた (about an equal)
友達に来てもらった
Using the causative about an equal implies you have power over them. Among equals, use ～てもらう (received the favor of coming): 友達に来てもらった (My friend came for me).
食べさす (ichidan shortened form)
食べさせる (ichidan keeps full form)
Only godan verbs can use the shortened causative: 書かす, 読ます, etc. Ichidan verbs always use the full -させる: 食べさせる, 見させる. 食べさす is dialectal and non-standard.
Frequently asked questions
How do I know if させる means "make" or "let"?
Context and particles give the primary clue. を + causative leans toward coercion ("make"). に + causative leans toward permission ("let"). But ultimately, the sentence context matters most. 子供にゲームをさせた could be either — you need the surrounding conversation to know if the parent is reluctantly allowing it or actively encouraging it.
What’s the difference between させてください and させていただけますか?
させてください (please let me) is polite. させていただけますか (might I be permitted to) is humble/honorific and used in business settings. させていただきます (I will humbly do) is the standard business opener: 説明させていただきます (Allow me to explain).
Can I use the causative for inanimate things?
Yes, in limited cases. エンジンを動かせる (make the engine run) uses causative-like logic but is technically a different verb (動かす). True causative is mainly for animate subjects being made/let to do things. For inanimate objects, Japanese usually uses a transitive verb instead.
What group does 走る belong to?