Look at these two sentences:
A. 休んでもらった。 → I asked you to rest. (I asked you to take a break.) B. 休ませてもらった。 → I asked (my boss) to let me rest. (I took time off.)
A is asking someone else to do something; B is asking someone to let you do something. One character apart, but the direction of the action is completely different.
てもらう Review
てもらう = asking someone else to do something for you.
- 友達に教えてもらった。 → I had my friend teach me. (The friend is the one performing the action.)
Causative + てもらう = Asking Permission to Do Something
Causative form + てもらう = asking someone to let you do something. You are the one doing the action, but you need the other person's permission.
-
休ませてもらった。 → I asked my boss to let me take time off. (I'm the one resting, but I needed my boss's approval.)
-
先に帰らせてもらいます。 → Please allow me to leave first. (I'm the one leaving, but I'm notifying the other person.)
Key point: With てもらう, the other person does the action. With させてもらう, you do the action yourself, but you need the other person's permission.
させてくれる / させてあげる
The same logic works with くれる and あげる:
| Expression | Meaning | Example |
|---|---|---|
| させてもらう | Please let me do (humble) | 休ませてもらう |
| させてくれる | They let me do (grateful) | 食べさせてくれる |
| させてあげる | Let someone do (benevolent) | 食べさせてあげる |
-
母はいつもおいしいものを食べさせてくれる。 → My mother always lets me eat delicious food. (Grateful to my mother.)
-
子供に好きなものを食べさせてあげる。 → I let the child eat what they like. (A favor I'm doing for the child.)
Note the difference with てあげる:
- 食べてあげる → I'll eat it for you. (I'm the one eating.)
- 食べさせてあげる → I'll let you eat. (You're the one eating.)
寝かせる vs 寝させる
Some verbs have both a transitive form and a causative form with different meanings:
| 寝かせる | 寝させる | |
|---|---|---|
| Nature | Transitive verb (to lay down) | Causative (to order/allow to sleep) |
| Nuance | A simple physical action | Has a commanding or permissive tone |
-
急救隊員は重傷者を病床に寝かせた。 → The paramedic laid the injured person on the hospital bed. (A simple physical action — placing someone on the bed.)
-
子供を早く寝させた。 → I made the child go to bed early. (An order/arrangement for the child to sleep.)
寝かせる = physical action (laying someone down). 寝させる = directive (making someone go to sleep).
Self-Test
Q1. You want to ask your boss for time off. How do you say it?
A. 休んでもらいたい B. 休ませてもらいたい
Show answer
B. 休ませてもらいたい. Asking your boss to let you rest = causative + てもらう. Option A would mean asking your boss to rest.
Q2. What is the difference between 「食べてあげる」 and 「食べさせてあげる」?
Show answer
食べてあげる = I'll eat it for you (the one eating is me). 食べさせてあげる = I'll let you eat (the one eating is you).
Summary
- てもらう = asking someone to do something (the other person does the action)
- させてもらう = asking someone to let you do something (you do the action)
- させてくれる = they let me do it (grateful), させてあげる = letting someone do it (benevolent)
- 寝かせる (transitive) = to lay someone down, 寝させる (causative) = to order/allow someone to sleep