Causative form (~せる・~させる)
Make or let someone do something
You'll be able to describe causing, requiring, or allowing another person to act.

母は芽衣に野菜を食べさせます。
haha wa mei ni yasai o tabesasemasu.
What do you think this sentence means?
My mother has Mei eat vegetables.
Make or let someone act
The causative describes causing or allowing another person to do something. Context decides whether it means making, having, or letting them act.
Group 1 · Godan
う → わせる
買う → 買わせる
kau → kawaseru
buy → causative form
く → かせる
書く → 書かせる
kaku → kakaseru
write → causative form
ぐ → がせる
泳ぐ → 泳がせる
oyogu → oyogaseru
swim → causative form
す → させる
話す → 話させる
hanasu → hanasaseru
speak → causative form
つ → たせる
待つ → 待たせる
matsu → mataseru
wait → causative form
ぬ → なせる
死ぬ → 死なせる
shinu → shinaseru
die → causative form
ぶ → ばせる
遊ぶ → 遊ばせる
asobu → asobaseru
play → causative form
む → ませる
読む → 読ませる
yomu → yomaseru
read → causative form
る → らせる
乗る → 乗らせる
noru → noraseru
ride → causative form
Group 2 · Ichidan
remove る + させる
食べる → 食べさせる
taberu → tabesaseru
eat → causative form
remove る + させる
見る → 見させる
miru → misaseru
see/watch → causative form
Group 3 · Irregular
special form
する → させる
suru → saseru
do → causative form
special form
来る → 来させる
kuru → kosaseru
come → causative form
Group 1 · Godan
Change the final u-row kana to the a-row and add せる. Final う uses わ: 買う→買わせる.
買う → 買わせる
kau → kawaseru
buy → causative form
書く → 書かせる
kaku → kakaseru
write → causative form
泳ぐ → 泳がせる
oyogu → oyogaseru
swim → causative form
話す → 話させる
hanasu → hanasaseru
speak → causative form
待つ → 待たせる
matsu → mataseru
wait → causative form
死ぬ → 死なせる
shinu → shinaseru
die → causative form
遊ぶ → 遊ばせる
asobu → asobaseru
play → causative form
読む → 読ませる
yomu → yomaseru
read → causative form
乗る → 乗らせる
noru → noraseru
ride → causative form
Group 2 · Ichidan
Remove final る and add させる. The resulting verb expresses causing or allowing the action.
食べる → 食べさせる
taberu → tabesaseru
eat → causative form
見る → 見させる
miru → misaseru
see/watch → causative form
Group 3 · Irregular
する becomes させる; 来る becomes 来させる (こさせる). The causative then conjugates like a Group 2 verb.
する → させる
suru → saseru
do → causative form
来る → 来させる
kuru → kosaseru
come → causative form
Form and use Causative form (~せる・~させる)
する→させる, 来る→来させる (こさせる), 買う→買わせる. With a transitive action, the person acting usually takes に and the object を. With an intransitive action, を often marks the person; に is also possible depending on agency and context.
父は子供を公園で遊ばせます。
chichi wa kodomo o kouen de asobasemasu.
My father lets the children play in the park.
母は子供に野菜を食べさせます。
haha wa kodomo ni yasai o tabesasemasu.
The mother makes her child eat vegetables.
先生は生徒に文を書かせました。
sensei wa seito ni bun o kakasemashita.
The teacher had the students write sentences.