Japanese Verbs Casuative Form, ~aseru ~ せる, ~saseru ~させる

Causative form are used to indicate an action that someone makes happen. The causative verb means to "make it so". This verb is usually used in the context of making somebody do something.

Japanese casuative form conjugation is very similar to a passive form conjugation. The causative forms are characterized by the final

• ~u becoming ~aseru for godan verbs, and
• ~ru becoming ~saseru for yodan stem verbs.

Group 1: ~ U ending verbs (godan)

to speak（話す） hanasaseru はなさせる hanasasemasu はなさせます
to write（書く） kakaseru かかせる　kakasemasu かかせます
to listen （聞く） kikaseru きかせる kikasemasu きかせます
to wait（待つ） mataseru またせる matasemasu またせます
to drink（飲む）nomaseru のませる nomasemasu のませます

Group 2: ~ Iru and ~ Eru ending verbs (yodan)

to wear （着る） kisaseru きさせる kisasemasu きさせます
to see （見る） misaseru みさせる misasemasu みさせます
to get up （起きる） okisaseru おきさせる okisasemasu おきさせます
to get off （降りる） orisaseru おりさせる orisasemasu おりさせます
to believe（信じる） shinjisaseru しんじさせる shinjisasemasu しんじさせます

Group 3: Irregular Verbs くる (kuru) and ~する (~suru)

to come (来る) kosaseru こさせる　kosasemasu こさせます
to do (する) saseru させる　sasemasu させます
to study（勉強する）benkyou-saseru べんきょうさせる benkyou-sasemasu べんきょうささせます

先生が学生に宿題をたくさんさせた。 sensei ga gakusei ni shoukutai wo takusansaseta - Teacher made students do lots of homework.

先生が質問をたくさん聞かせてくれた。sensei ga shitsumon wo takusan kikasete kureta
- Teacher let [someone] ask lots of questions.

今日は仕事を休ませてください。kyou wa shigoto wo yasumasete kudasai
- Please let me rest from work today. (Please let me take the day off today.)

その部長は、よく長時間働かせる。sono buchyou wa yoku chyojikan hatarakaseru
- That manager often make [people] work long hours.

Asking for permission

When asking for permission to let someone do something, it is more common to use the ～てもいい (te moii) grammar.

Compare:

• トイレに行かせてくれ か。toire ni ikasete kuremasu ka - Can you let me go to the bathroom? (Sounds like a prisoner, even in English)


• トイレに行ってもいいですか。toire ni itte moii desuka - Is it ok to go to the bathroom? (much better here)

Letting (somebody) to do (something)

It can also mean to let someone do something. A verb in the causative form can mean either making or letting someone do something. When the causative form is used with あげる (ageru) and くれる (kureru), it almost always means to "let someone do".

全部食べさせた。zenbu tabesaseta - Made/Let (someone) eat it all.
全部食べさせてくれた。zenbu tabesasete kureta- Let (someone) eat it all.

Rough Slang Casuative Form

There is a shorter version of the causative conjugation mostly used in very rough slang. Textbooks usually don't cover this version of the causative verb.Skip it if don't need.

The first part of the conjugation is the same as the original causative form. However, for godan u-verbs, you attach す ~su instead of せる ~ seru, and for yodan ru-verbs, instead of using させる (~saseru) , you attach さす ~sasu.

As a result, all the verbs become an u-verb ending in す ~su.

• 同じことを何回も言わすな！ onaji koto wo nankai mo iwasu na - Don't make me say the same thing again and again!

• お腹空いているんだから、なんか食べさしてくれよ。onaka akuiteirun dakara, nanka tabesashite kuryo - I'm hungry so let me eat something.