Japanese Causative: V-せる／させる & “(Causer) は (Causee) に V-せる/させる”

Introduction

Want to say “I made my brother clean his room” or “My parents let me live alone” in Japanese? You’ll use the causative:

• V-せる／させる (verb form)
• (Causer) は (Causee) に V-せる/させる (sentence pattern)

This form covers both “make someone do” and “let/allow someone to do.”

1. What the causative means

The causative expresses the idea of causing or permitting an action:

• [make someone do something]
  母ははは私わたしに野菜やさいを食たべさせました。
  My mother made me eat vegetables.
• [let / allow someone to do something]
  私わたしは息子むすこに好すきなことをさせます。
  I let my son do what he likes.

We’ll build the verb first (V-せる／させる), then plug it into the sentence pattern.

2. How to form the causative (V-せる／させる)

Ru-verbs

Drop the final -ru and add -saseru.

U-verbs

Drop the final -u and add -aseru.
For verbs ending in う, add -waseru.

Irregular verbs

3. The core sentence pattern

Structure: (Causer) は/が (Causee) に (Object) を [Causative Verb].

Example：先生せんせいは生徒せいとに漢字かんじを書かかせました。
The teacher made the students write kanji.

に vs を with intransitive verbs

With intransitive verbs (= verbs that do not take a direct object), the causee may be marked by either に or を.

In general:

• に tends to show letting / allowing
• を tends to show making / causing

However, this is not a strict rule. The nuance depends a lot on the context.

1) Cases where both に and を are possible

• 先生せんせいは学生がくせいに授業中じゅぎょうちゅうにお手洗てあらいに行いかせました。
  The teacher let the student go to the restroom during class.
• 先生せんせいは学生がくせいを授業中じゅぎょうちゅうにお手洗てあらいに行いかせました。
  The teacher made/sent the student go to the restroom during class.

Both are possible, but the nuance is slightly different. に sounds more like giving permission, while を sounds more like making or causing the action.

2) Cases where に is natural

• 母親ははおやは子こどもにゲームで遊あそばせました。
  The mother let her child play a video game.

Here, に is natural because the sentence focuses on allowing the child to do something.

3) Cases where を is natural

• 先生せんせいは風邪かぜをひいた生徒せいとを帰かえらせました。
  The teacher made the student who had caught a cold go home.

Here, を is natural because the sentence focuses on the teacher causing the student to leave.

4. Examples you’ll actually say

部長ぶちょうは私わたしに電話でんわをかけさせました。
The department head had me make the call.

後輩こうはいに迎むかえに来こさせます。
I’ll have a junior come pick (me) up.

後輩こうはいにコピーを取とらせます。
I’ll make a junior make copies.

娘むすめに 一人ひとり 暮ぐらしをさせます。
I let my daughter live alone.

子こどもに好すきなことをさせたいです。
I want to let my children do what they like.

5. Quick build—mini conjugation drill

Turn each into causative:

• 食たべる → 食べさせる
• 考かんがえる → 考えさせる
• 働はたらく → 働かせる
• 聞きく → 聞かせる
• 来くる → 来こさせる

6. Common mistakes (and fixes)

7. Practice time!

Make causative sentences from the cues:

8. FAQ

Conclusion

You can now:

• Build causative verbs (ru→させる, u→a-row + せる; ～う → わせる; する→させる; 来る→来させる).
• Write causative sentences with (Causer) は/が (Causee) に (Object) を [Causative Verb] and handle に／を with intransitives based on context.
• Say both “make” and “let/allow” naturally with real examples.

Practice with three real situations from your life (at school, home, or work). Once you can swap in に／を confidently and conjugate on the fly, causatives will start to feel automatic.