Causative Form (〜させる): How to Say Make or Let Someone Do
What it means
The causative says that one person causes another to do an action. In English we split this into two ideas — "make someone do" (force) and "let someone do" (allow) — but Japanese uses the same form for both. The surrounding context, tone, and particles tell you which meaning is intended.
So 子供を行かせる can mean "I make the child go" (an order) or "I let the child go" (permission), depending on the situation. A polite request like 〜させてください ("please let me…") almost always means the permission sense.
先生はヤッタンに漢字を書かせた。
せんせいは ヤッタンに かんじを かかせた。
The teacher made Yattan write kanji.
Coercion sense — the teacher gave the order.
お母さんはヤッタンを公園で遊ばせた。
おかあさんは ヤッタンを こうえんで あそばせた。
Yattan's mom let him play in the park.
Permission sense — same form, allowed rather than forced.
モチはヤッタンの弟に野菜を食べさせた。
モチは ヤッタンの おとうとに やさいを たべさせた。
Mochi made Yattan's little brother eat his vegetables.
How to form it
There are two endings — せる for う-verbs and させる for る-verbs — plus the two irregulars.
| Verb type | Rule | Example |
|---|---|---|
| る-verbs | drop る, add させる | 食べる → 食べさせる |
| う-verbs | final u-sound → a-sound, add せる | 書く → 書かせる |
| う-verbs | (more) | 読む → 読ませる, 言う → 言わせる |
| する (irregular) | → させる | する → させる |
| 来る (irregular) | → 来させる | 来る → 来させる (こさせる) |
One spelling trap: for う-verbs ending in 〜う (like 言う, 買う), the a-sound is わ, not あ — 言わせる, 買わせる. The whole 〜せる / 〜させる verb then conjugates as a normal る-verb (食べさせない, 食べさせた, 食べさせます).
Make vs. let — how context decides
Because one form carries both meanings, look at the situation and the relationship between the people:
部長は社員を残業させた。
ぶちょうは しゃいんを ざんぎょうさせた。
The manager made the employees work overtime.
A boss ordering subordinates → coercion.
ヤッタンが頼んだので、先生は早く帰らせてくれた。
ヤッタンが たのんだので、せんせいは はやく かえらせて くれた。
Because Yattan asked, the teacher let him go home early.
A request granted → permission.
When the doer wants to do the action and the causer simply allows it, it reads as "let." When the doer is being pushed into it, it reads as "make."
The particle rule: を vs. に
This is the part to memorize. It depends on whether the verb already has its own object.
- Intransitive verbs (no direct object, like 行く, 来る, 帰る): the person made/let to act takes を.
- Transitive verbs (already have a を object, like 食べる, 読む): the person takes に, because を is "busy" marking the real object.
ヤッタンを行かせる。
ヤッタンを いかせる。
(I) make Yattan go.
行く is intransitive → the person takes を.
ヤッタンに本を読ませる。
ヤッタンに ほんを よませる。
(I) make Yattan read a book.
読む already has its を object (本), so Yattan takes に.
モチは弟にミルクを飲ませた。
モチは おとうとに ミルクを のませた。
Mochi made/let the little brother drink the milk.
飲む is transitive → person takes に.
A sentence almost never has two を, so when the verb already uses を for its object, the caused person shifts to に.
"Please let me…" — 〜させてください
Put the causative into its て-form and add ください and you get a polite way to ask for permission to do something yourself: 〜させてください = "please let me…." This is one of the most useful everyday uses of the causative.
すみません、ここで写真を撮らせてください。
すみません、ここで しゃしんを とらせて ください。
Excuse me, please let me take a photo here.
少し考えさせてください。
すこし かんがえさせて ください。
Please let me think about it for a bit.
You may also meet the causative-passive (使役受身, e.g. 食べさせられる, "to be made to eat"), which combines this form with the passive to say you were forced to do something. That's a separate N4 point worth studying after you're comfortable with the plain causative here.
Common mistakes
- Mixing up せる and させる. る-verbs (and 来る) take させる; う-verbs take just せる. 食べる→食べさせる (✓), not 食べせる.
- Putting を on the person when the verb is transitive. With 食べる, 読む, 飲む, etc., the caused person takes に: 弟に野菜を食べさせる (✓), not 弟を野菜を食べさせる.
- Forgetting the わ for 〜う verbs. 言う → 言わせる, not 言あせる.
- Assuming させる only means "force." It also means "let/allow." Tone and context — not the verb form — tell you which. 〜させてください is always the polite "let me" sense.
Quick recap
- Causative = make or let someone do something; one form, both meanings.
- Form it: る-verbs → drop る + させる; う-verbs → u-sound to a-sound + せる; する→させる, 来る→来させる.
- Intransitive verb → caused person takes を; transitive verb → caused person takes に.
- 〜させてください = "please let me…" (asking permission).
- The causative-passive (〜させられる) is the related "was forced to do" form.
Your turn
Form the causative and pick the right particle (を or に).
Start the 5-question drill →Take the full N4 causative drill →
Frequently asked questions
Does させる mean 'make' or 'let'?
Both. The causative form is identical for coercion ('make someone do') and permission ('let someone do'). Context, tone, and the relationship between the people tell you which. A request like 帰らせてくれた reads as 'let,' while a boss's order reads as 'make.'
When do I use を and when do I use に for the person?
If the verb is intransitive (行く, 来る), the caused person takes を: ヤッタンを行かせる. If the verb is transitive and already has a を object (本を読む), the person takes に instead: ヤッタンに本を読ませる. Japanese avoids two を in one clause.
How do I form the causative of する and 来る?
They're irregular: する → させる, and 来る → 来させる (read こさせる).
What does 〜させてください mean?
It's the て-form of the causative plus ください, used to politely ask permission to do something yourself: 少し休ませてください ('please let me rest a bit').