58 Japanese Conjugations of the verb Suru

This guide presents 58 fundamental conjugations, categorized by usage groups. Each conjugation is accompanied by clear explanations and practical sentences so that you can internalize and apply them with confidence.

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Forms of Affirmation and Negation — Present and Past

These are the essential forms to talk about simple actions in the present or past, affirming or denying.

する

The form of the dictionary. Used in neutral sentences, titles, combinations with nouns. The starting point for all others.

毎日運動する。
Mainichi undō suru.

I exercise every day.

しない

Negative in the present (informal). It is used to indicate that one does not do or one will not do something. Very common in everyday conversations.

今日は何もしない。
Kyō wa nani mo shinai.

Today I'm not going to do anything.

します

Polite form of する. Ideal for professional contexts, customer service, or any respectful interaction.

あとで電話します。 
Ato de denwa shimasu. 

I'll call later.

しません

Polite negative. You will use it in situations where declining an action needs to maintain a courteous tone, such as in emails or stores.

魚は食べませんし、料理もしません。
Sakana wa tabemasen shi, ryōri mo shimasen.

I don't eat fish and I also don't cook.

した

Informal past. Indicates that the action was done. Quick, direct, and casual.

昨日、掃除した。
Kinō, sōji shita.

I cleaned yesterday.

しなかった

Informal negative past. Perfect for reporting that something was not done. Widely used in everyday life.

週末に宿題をしなかった。
Shūmatsu ni shukudai o shinakatta.

I didn't do the homework over the weekend.

しました

Polite version of した. Used when reporting something that was done in a more respectful tone.

先月、大きな決断をしました。
Sengetsu, ōkina ketsudan o shimashita.

Last month, I made a big decision.

しませんでした

Formal negative form in the past. You say that you did not carry out an action and still sound polite.

昨日は運動をしませんでした。
Kinō wa undō o shimasen deshita.

Yesterday, I didn't work out.

Shape and Derivations

The form て serves as a basis for connecting sentences, making requests, instructions, and many compound constructions.

して

The て form of する. It is used to link actions ("do this and...") or to use with auxiliaries like いる (to be), ください (please), しまう (end up doing), みる (to try doing), among others.

部屋を片付けて、勉強して。
Heya o katazukete, benkyō shite.

Clean the room and study.

しないで

Negative form of て. Used to instruct someone to not do something before another action, or to deny an instruction.

心配しないでください。
Shinpai shinai de kudasai.

Please don't worry.

Volition, Intention, and Desire

These forms indicate wants, plans, and desires, both of the speaker and of other people.

したい

Express a personal desire to do something. Very commonly used in informal contexts to indicate willingness.

日本に行って、旅行したい。
Nihon ni itte, ryokō shitai.

I want to go to Japan and travel.

したくない

Negation of the form of desire. It serves to say that you do not want to do something.

今日は外出したくない。
Kyō wa gaishutsu shitakunai.

Today I don't want to go out.

したかった

Past form of desire. When one wanted to do something, but the time has already ed.

I actually wanted to do that for a long time.
Actually, I always wanted to do that.

Actually, I've always wanted to do this.

したくなかった

Negative form of the past of desire. When did not want to do something, but needs to report this.

本当は行きたくなかったし、何もしたくなかった。
Hontō wa ikitakunakatta shi, nanimo shitakunakatta.

I really didn't want to go, or do anything.

したがる

Used to indicate that another person seems to want to do something, describing a perceived desire of others. The desire is perceived through actions or attitudes, not directly stated.

子供は一人でやりたがる。
Kodomo wa hitori de yaritagaru.

The child wants to do it by herself.

したがらない

Negation of したがる. Indicates that the other person shows not wanting to do something.

彼は全然話したがらない。
Kare wa zenzen hanashitagarana i.

He does not want to talk at all.

Causative and Permissive

These forms demonstrate situations in which someone is induced, forced, or authorized to do something.

させる

Causative form. You make someone do or allow someone to do. It can be used in a tone of authority or permission.

先生が生徒に挨拶をさせる。
Sensei ga seito ni aisatsu o saseru.

The teacher makes the students greet each other.

させない

Negation of the causative. It indicates that you do not allow or do not force someone to perform an action.

彼は私に説明させない。
Kare wa watashi ni setsumei sasenai.

He doesn't let me explain.

させた

Causative in the past. It shows that someone was led to do something previously.

母が私を料理させた。
Haha ga watashi o ryōri saseta.

My mother made me cook.

させなかった

Negation of the causative in the past. You prevented someone from carrying out an action.

彼女は彼を行かせなかった。
Kanojo wa kare o ikasenakatta.

She didn’t let him go.

Prohibitions and Direct Orders

These forms are used to give orders, prohibit or directly instruct someone. Some are harsh, while others are more polite.

しろ

Direct and informal order. It can sound authoritative, common among men or in military/anime contexts.

黙ってしろ！
Damatte shiro!

Shut up and do this!

するな

Negative imperative form. It means: "Don't do that!". It can be blunt.

それをするな！
Sore o suru na!

Do not do it!

やれ

Another imperative. It is an alternative form, commonly used with verbs like やる (do), which replaces する in some contexts.

早くやれ！
Hayaku yare!

Do it soon!

やるな

Imperative negation of やる. It also means "Don't do it!", but with a rougher tone.

ふざけるな、やるな！
Fuzakeru na, yaru na!

Stop joking, don’t do that!

Expressions of Intention, Plans, and Expectations

These forms show planning, intention, or something that is expected to happen.

しよう

Informal volitional form. Used to say "I will do" or "let's do." It is a way to suggest or motivate oneself.

明日は早く起きて勉強しよう。
Ashita wa hayaku okite benkyō shiyō.

Tomorrow I will wake up early and study.

しましょう

Formal volitional. Used for polite invitations, meetings, or respectful proposals.

一緒に手伝いましょうか？
Issho ni tetsudaimashō ka?

Shall we help together?

するつもり

Indicates firm intention. It's like saying "I intend to do."

来週からダイエットするつもりです。
Raishū kara daietto suru tsumori desu.

I intend to start a diet next week.

Others’ Wishes and Requests

These forms permitem express what you want someone to do, or what someone seems to want to do. This is where respect, empathy, and reading the other person come into play.

してほしい

Express that you wish for someone else to do something. Very common in interpersonal relationships and used carefully so as not to sound bossy.

もっと早く返事してほしい。
Motto hayaku henji shite hoshii.

I wanted you to respond faster.

してほしくない

Negative form. Used to say that you would prefer that the person not do a certain action. Ideal for conveying boundaries with delicacy.

そんなこと言ってほしくない。
Sonna koto itte hoshikunai.

I would prefer that you didn't say that.

Involuntary Action or Regret

These constructions indicate that something was done unintentionally, was unavoidable, or had an undesirable consequence.

してしまう

It means "to end up doing" or "to do accidentally." It's a useful way to report slips or actions that got out of control.

寝坊してしまった。
Nebō shite shimatta.

I ended up losing track of time.

しちゃう

Informal and contracted version of してしまう. Very commonly used in everyday speech and among young people.

またスマホ見ながら寝落ちしちゃう。
Mata sumaho mi nagara neochi shichau.

I'm going to end up sleeping again while looking at my phone.

しちゃった

Informal past of しちゃう. It translates to "I ended up doing...".

間違えて送信しちゃった。
Machigaete sōshin shichatta.

I ended up sending it by mistake.

しちゃいました

Polite form of the past. Good for when you want to acknowledge a mistake or something inevitable with respect.

すみません、間違えて押しちゃいました。
Sumimasen, machigaete oshichaimashita.

Sorry, I pressed the wrong button by mistake.

Vulgarity and Rustic Language

These forms are not recommended for formal contexts. They appear in animes, movies, or conversations between close people with rude language.

しゃがる

A vulgar way of "doing" with a disdainful or aggressive tone. It can sound offensive depending on the context.

また変なことしゃがるなよ。
Mata hen na koto shagaru na yo.

Here he comes to mess things up again.

しゃがった

Past of the previous form. It carries the same emotional weight or harshness as the base version.

あいつ昨日も騒ぎしゃがったよ。
Aitsu kinō mo sawagi shagatta yo.

That guy caused a scene again yesterday.

Expressions of Prohibition and Permission

Here are structures that indicate what is or is not allowed to be done. Very common in rules, warnings, recommendations, and social interactions with limits.

してもいい

Indicates permission: "can do". Used to give authorization or confirm if something is acceptable.

ここに座ってもいいですか？
Koko ni suwatte mo ii desu ka?

May I sit here?

しなくてはいけない

Forces someone to do something: "has to do it". Used with a sense of duty.

早く準備しなくてはいけない。
Hayaku junbi shinakute wa ikenai.

I need to prepare quickly.

してはいけない

Prohibition: "you cannot do." A common phrase in school rules, manuals, and social norms.

試験中はスマホを使ってはいけない。
Shikenchū wa sumaho o tsukatte wa ikenai.

Cell phones cannot be used during the exam.

しなければならない

More formal version of しなくてはいけない. Expresses unavoidable or normative obligation.

この書類は提出しなければならない。
Kono shorui wa teishutsu shinakereba naranai.

This document must be submitted.

してはならない

More rigid and formal. Used in legal, educational, or institutional contexts.

公共の場で大声で話してはならない。
Kōkyō no ba de ōgoe de hanashite wa naranai.

One should not speak loudly in public places.

Planning and Expectation Expressions

These forms are used to convey planned intention or opinion about what is right.

するつもり

Show intention: "I intend to do". Used for defined plans, but still future.

するべき

It means "should do". It points to something morally or logically correct.

約束は守るべきだと思います。
Yakusoku wa mamoru beki da to omoimasu.

I think promises should be kept.

するべきだった

Expresses regret: “I should have done”. A reflection on something that was not done in the past.

もっと早く準備するべきだった。
Motto hayaku junbi suru beki datta.

I should have prepared myself earlier.

するべきじゃなかった

Opposite of the previous: "shouldn't have done that." Carries emotional weight or guilt.

あの話はするべきじゃなかったと反省している。
Ano hanashi wa suru beki janakatta to hansei shite iru.

I regret having said that.

するべきでした

The polite and formal version of するべきだった.

ご連絡するべきでしたが、遅れてしまいました。
Gorenraku suru beki deshita ga, okurete shimaimashita.

I should have gotten in touch, but I was late.

するべきではありませんでした

Extremely polite form. Used to formally apologize or to express regret with great respect.

本当に申し訳ありません、言うべきではありませんでした。
Hontō ni mōshiwake arimasen, iu beki de wa arimasen deshita.

I'm sorry, I shouldn't have said that.

Assumptions, Opinions, and Indirect Remarks

These forms are used to suggest, suppose, remind, or comment on actions in an indirect way.

するらしい

Expresses assumption: "it seems like it will make" or "I heard it does." Light and useful for gossip or indirect information.

彼は明日も来るらしいよ。
Kare wa ashita mo kuru rashii yo.

It seems that he is coming tomorrow too.

するそうですよ

A slightly more assertive and conversational way of expressing this would be to convey the information as if it were shared by someone.

田中さん、今夜飲み会に行くそうですよ。
Tanaka-san, kon'ya nomikai ni iku sō desu yo.

Tanaka is going to the gathering tonight, you know.

するんだっけ？

Used to confirm something that was forgotten: "it was supposed to be done, right?". Very common in informal conversation.

これって自分でするんだっけ？
Kore tte jibun de suru n da kke?

This was supposed to be something I did alone, right?

するんでしたっけ？

A slightly more polished version of the previous one. It also seeks confirmation about something that was heard or planned.

宿題を提出するんでしたっけ？
Shukudai o teishutsu suru n deshita kke?

It was supposed to hand in the assignment, right?

Conditions and Hypotheses

Here are ways that talk about possibilities, conditions, and hypothetical consequences, very useful in dialogues and argumentative writing.

するかもしれない

It may happen. It expresses uncertainty or a possibility.

彼はまだ来るかもしれない。
Kare wa mada kuru kamo shirenai.

Maybe he will still come.

しないかもしれない

Negative of the previous one. Indicates that perhaps it will not be done.

明日は雨だから出かけないかもしれない。
Ashita wa ame da kara dekakenai kamo shirenai.

Maybe I won't go out tomorrow because of the rain.

すれば

Affirmative conditional. "If you do..." — introduces a consequence or suggestion.

努力すれば、夢は叶う。
Doryoku sureba, yume wa kanau.

If you put in the effort, your dreams come true.

しなければ

Negative conditional. “If you don’t do… ” — shows the risk or consequence of omission.

参加しなければ、結果も出ない。
Sanka shinakereba, kekka mo denai.

If you don't participate, you also won't have results.

したとしたら

"If I had only done..." — used in hypotheses or reflections. It carries the idea of supposition about the past.

もし彼が嘘をついたとしたら？
Moshi kare ga uso o tsuita to shitara?

What if he lied?

しなかったとしたら

Opposite of the previous one: "if I hadn't done...". Excellent for speculating or imagining alternative scenarios.

勉強しなかったとしたら、今ごろ大変だった。
Benkyō shinakatta to shitara, imagoro taihen datta.

If I hadn't studied, I would be in trouble now.

Other Conjugations of する

To finish, let's share other conjugations that do not appear in other categories.

するって

Contraction or informal way to say that someone said "they will do". Common in casual conversation.

せしめる（為しめる）

An ancient and extremely formal form of the causative of する. Practically dead in modern use, but appears in documents or classical literature.

王は民に命令を為しめた。
Ō wa tami ni meirei o seshime ta.

The king made the people obey.

す（為）

Classic form of する used in ancient texts, poetry, Buddhism, and traditional Japanese literature. It appears in hymns and teachings.

善をすれば善が返る。
Zen o sureba zen ga kaeru.

If you do good, good will return.