Making and Letting with the Causative Form

What is the Causative Form

The causative form is used when you want to say that someone makes or lets someone else do an action. In Japanese, the same conjugation is used for both forcing an action (making) and permitting an action (letting). The correct meaning is usually clear from context or from other grammar patterns attached to the verb.

When reading or listening, you can spot the causative form by looking for the syllables or attached to the end of a verb stem.

Conjugation Patterns

To conjugate a verb into the causative form, you must modify its dictionary form depending on which of the three verb groups it belongs to.

1. Ru-Verbs

For ru-verbs (Ichidan), simply drop the final and attach .

Base Form	Causative Form	Meaning
		To make/let eat
		To make/let see
		To make/let wake up

Examples

2. U-Verbs

For u-verbs (Godan), drop the final "u" vowel, change it to the "a" vowel of the same row, and then attach . If the verb ends in the vowel by itself, it changes to instead of "あ".

Base Form	Change	Causative Form	Meaning
	く → か		To make/let go
	む → ま		To make/let drink
	す → さ		To make/let speak
	つ → た		To make/let wait
	う → わ (Exception)		To make/let buy

Examples

3. Irregular Verbs

The two irregular verbs simply need to be memorized.

Base Form	Causative Form	Meaning
		To make/let do
		To make/let come

Examples

Particle Usage

When using the causative form, you need to assign particles to show who is causing the action and who is performing the action. The rules for this depend on whether the original verb is transitive or intransitive. You can read more about standard particles in the Introduction to Japanese Particles guide.

Intransitive Verbs

If the verb does not take a direct object (like running, going, or sleeping), the person who is made or allowed to do the action is marked with the particle .

Director Actor Causative Verb

Transitive Verbs

If the verb takes a direct object (like eating an apple, or reading a book), the direct object already uses the particle . Because you generally cannot have two particles in the same clause, the person performing the action is marked with the particle instead.

Director Actor Object Causative Verb

Make versus Let

Because the same conjugation is used for both forcing ("make") and allowing ("let"), Japanese relies heavily on context and helper verbs to clarify the speaker's intent.

Making Someone Do Something

When a person in a higher social position (like a boss, teacher, or parent) uses the bare causative form toward someone in a lower position, it almost always implies forcing or directing.

Letting Someone Do Something

If the context is positive, the bare causative form can mean "let." For instance, if a child asks to play outside, a parent might say they will "let" them.

However, to make it explicitly clear that the action is a welcomed permission rather than a forced task, speakers frequently combine the causative form with giving and receiving verbs like or .

By adding , the speaker clarifies that the causative action ("letting me play") is received as a favor. You can learn more about how this works in the Giving and Receiving Verbs Ageru, Kureru, Morau guide.

Causative Form in Formal Settings

When using the causative form in business or formal settings, the base causative sound of or should be replaced with humble (Kenjōgo) verbs. Instead of saying (I'll humbly make/let do), a more natural formal construction would be , using the humble verb to soften the causative request.

This is an important element of Japanese Honorifics Sonkeigo and Kenjougo, where making or letting someone do something must be framed with appropriate social distance to avoid sounding demanding.

Permission Patterns vs Causative Form

It is important to distinguish between the causative form (which involves a person causing or allowing another person to act) and simple permission patterns that describe whether an action is generally allowed.

Causative form: When you "let someone do" something, you are actively permitting a specific person to perform an action. For example, This describes a parent giving permission to the child.
Permission patterns: These describe whether something is generally acceptable or prohibited in a given context, without necessarily involving a specific person granting that permission. For example,

Both the causative form and permission patterns appear frequently in requests and responses involving permission. For a comprehensive guide on ～てもいい, ～てはいけない, and other patterns for expressing rules, obligations, and lack of necessity, see Permission and Prohibition in Japanese.

Study Tips

The causative form is very common, especially in formal speech and professional settings. When learning it, try to focus on recognizing the and sounds at the ends of verbs. Once you can consistently identify when a sentence is using the causative, you will quickly pick up on the context of who is making or letting whom do what.

Rather than running through conjugation drills, spend your time engaging with Japanese media. Through A Practical Guide to Language Immersion, you will naturally encounter the causative form in native sentences, which will build your intuitive understanding of the difference between "make" and "let" much faster than memorizing rules.

Finally, keep an eye out for the causative-passive form. This is an advanced conjugation that combines the causative with the Expressing Actions with the Passive Form to express being forced to do something against your will. Understanding the basic causative first makes the causative-passive much easier to digest when you inevitably encounter it.