Video
Let’s watch this short video for a quick overview.
Source: gokigen japanese official YouTube Channel
Introduction
Most Japanese verbs follow regular patterns — either as ru-verbs or u-verbs. But there are a couple of important exceptions you absolutely need to know:
する (to do) and くる (to come).
These are called irregular verbs, and while they don’t follow the usual rules, they’re incredibly useful and common in daily conversation.
In this article, you’ll learn:
✔ How to conjugate する and くる into polite forms
✔ Example sentences using these verbs naturally
✔ A list of common “する-verbs” you’ll see everywhere
✔ How to practice and avoid common mistakes
✔ An FAQ section with bonus tips
Let’s tackle these powerful verbs!
1. What Are Irregular Verbs in Japanese?
Japanese has two main irregular verbs:
| Verb | Meaning |
|---|---|
| する | to do |
| 来る（くる） | to come |
They don’t follow the rules of ru-verbs or u-verbs. You simply need to memorize their conjugation patterns — but don’t worry, they’re used so often you’ll remember them fast!
2. How to Conjugate する and くる
Polite Present Forms
| Dictionary | Polite | Polite Negative |
|---|---|---|
| する | します | しません |
| くる | きます | きません |
Note: The stem of くる changes to き in the polite form — it’s unique!
3. Real-Life Sentence Examples
| Japanese | Romaji | English |
|---|---|---|
| 日本語をべんきょうします。 | nihongo o benkyo shimasu | I study Japanese. |
| 日本語をべんきょうしません。 | nihongo o benkyo shimasen | I don’t study Japanese. |
| 先生が来ます。 | sensei ga kimasu | The teacher is coming. |
| 先生が来ません。 | sensei ga kimasen | The teacher is not coming. |
4. Common “する-Verbs” You Should Know
The verb する is super flexible! It attaches to many nouns to form compound verbs.
| Noun + する | Meaning |
|---|---|
| べんきょう + する → べんきょうする | to study |
| れんしゅう + する → れんしゅうする | to practice |
| よやく + する → よやくする | to make a reservation |
| そうじ + する → そうじする | to clean |
| しごと + する → しごとする | to work |
Conjugation is just like する:
- よやく します
- れんしゅう しません
- そうじ しました（past tense）
5. Practice Time: Try Conjugating These!
| Verb | Polite | Polite Negative |
|---|---|---|
| する（to do） | します | しません |
| べんきょうする（to study） | べんきょうします | べんきょうしません |
| くる（to come） | きます | きません |
| そうじする（to clean） | そうじします | そうじしません |
✅ Try saying these aloud or writing them in your notebook!
6. FAQ – Frequently Asked Questions
- QIs くる the only verb that uses “きます”?
- A
It’s the polite form of くる (kuru), which means “to come.” Be careful not to confuse it with 着ます (kimasu), which comes from the verb 着る (kiru), meaning “to wear” or “to put on (clothes).”
Although they look and sound the same in the polite form (きます),
- きます (from 来る) = “to come” (irregular verb)
- きます (from 着る) = “to wear” (る-verb / ichidan verb)
The meaning and conjugation patterns are different, so pay attention to the kanji!
- QCan I use する with any noun?
- A
Not all nouns, but many activity-related nouns can be combined with する.
- QAre there irregular verbs beyond する and くる?
- A
These are the only two truly irregular verbs. Some verbs like いく have irregular forms in specific tenses (like いって), but they’re still classified as regular u-verbs.
7. Conclusion: Power Up Your Japanese with する and くる!
Irregular verbs may sound intimidating, but in Japanese, there are just two to remember — and both are super useful!
By mastering する and くる, you’ll open the door to expressing actions, movement, and tons of useful daily expressions.
🎯 Your next step: Try using べんきょうする and きます in a few example sentences of your own!
Want to improve your Japanese with real conversations?
Our native Japanese instructors at gokigen japanese can help you perfect your pronunciation and learn real-life usage.
Whether you’re completely new to Japanese or looking to refine your skills, book a one-on-one session.
