The Causative Form

The causative form is used to describe when someone or something has made something happen or, as the name suggests, causes something to happen.

Using the Causative Form

Sentences in the causative form usually need a causer, an actor and an action.

Take the following sentence:

• お母さんは子供に果物を食べさせました。
  The mother made the child eat the fruit.

The causer (お母さん) is marked by the particle は or が, the actor (子供) is marked by the particle に and the verb is conjugated to the causative form.

Conjugation the Causative Form

U-Verbs

For u-verbs that end in the kana う, take the dictionary form, remove the う, replace it with わ and then add せる.

Dictionary Form	Causative Form
買う	買わせる

For all other u-verbs, replace the u-vowel sound with the a-vowel equivalent and then attach せる.

Dictionary Form	Causative Form
待つ	待たせる
飲む	飲ませる
泳ぐ	泳がせる
行く	行かせる

You may have noticed the first steps of conjugating the causative form follow the same pattern as conjugating the nai-form. Only the final step is different, adding せる instead of ない.

Ru-Verbs

For ru-verbs, take the dictionary form, cut the る and add させる.

Dictionary Form	Causative Form
食べる	食べさせる
見る	見させる
覚える	覚えさせる

Irregular

Dictionary Form	Causative Form
する	させる
くる	こさせる

Each of these verbs in the causative form are effectively new verbs in the ru-form and can be conjugated further to the te-form, masu-form etc.

Example Sentences

• アレルギーがあるのに私が子どもに卵を食べさせてしまった。
  Even though she's allergic, I gave an egg to the child.

• 私が友達に宿題をチェックさせた。
  I had my friend check my homework.

• 飲食代を払わせる。
  To make a person pay for food.

• 待たせてごめんなさい。
  Sorry I made you wait.