In order to express that someone was ‘made to do’, or ‘let do’ something, the auxiliary verbs せる
will be used. The meaning that せる
will convey (when attached to a verb) is called 使役（しえき） (causative, employment, or using) in Japanese.
A common misconception is that せる
are standard conjugations of each verb. However, these auxiliary verbs should be thought of as having their own meaning, in a similar way to how たい
, ない, だ
, and other auxiliaries each have their own meanings.
In order to use these grammar structures, remove the る from る-Verbs
, and then add させる
. For う-Verbs
, change the last kana to the あ sound kana from within the same column (except for う, which becomes わ), and then add せる (る becomes ら, む becomes ま, く becomes か, etc.).
I make my son eat vegetables.
I make my friend grow tomatoes.
At the end of year party, the seniors made the juniors sing a song.
Since my friend broke my phone, I will make them buy me a new one.
As usual, する
have special conjugation rules. する
will be replaced completely be させる
(in a similar way to how できる
completely replaces する
in the ‘potential
’ form). 来（く）る
will become 来（こ）させる
I let my juniors do the work that I don't want to do.
You should not do anything that would make your parents worry.
It is not good to make people come to the company late at night.
To call the dog and make it come to you.
With causative, either に
, or を
can mark the doer of the action that せる, or させる is linked to (not が). This is because the actual ‘doer’ of the action is considered to be the person that is making/letting someone perform that action. に
will usually imply that someone was ‘let’ do something, while を
Because the actual ‘doer’ in causative verb sentences will be marked with が (as is always the case), the literal translation of せる and させる is closer to the following:
(A) が (B) に楽しませる - For (A) to cause fun ‘in’ (B).
(A) が (B) を楽しませる - For (A) to cause fun ‘through’ (B).
It is these standard meanings of the particles に (a location) and を (a target) that will create the ‘let’, or ‘make’ nuance when using せる, or させる.