Suru vs Yaru: When to Use Each Japanese Verb for Do

Suru: the neutral verb that fits everywhere

Suru is the safest verb in Japanese. It is neutral in register, so it sounds right in a text to a friend, an email to a client and a school essay. Its polite form is shimasu, its past form is shita, and the -te form is shite. Because it is so neutral, it is the default when you are not sure how close you are to the listener.

Suru takes a direct object with o: shukudai o suru, to do homework; ryōri o suru, to cook; sōji o suru, to clean. It also describes wearing accessories, nekutai o suru, to wear a tie, and choosing something, kōhī ni suru, to go with coffee. These extended uses are why suru is worth learning deeply rather than treating it as a plain translation of do.

Yaru: plain, physical and personal

Yaru also means to do, but with a different flavour. It is casual, so it belongs in conversations with friends, family and colleagues you are relaxed with. It also feels more hands-on and physical than suru. Shigoto o yaru, to do the work, sounds like rolling up your sleeves, whereas shigoto o suru simply reports that work happens.

The polite form yarimasu is common in relaxed workplaces, especially watashi ga yarimasu, I'll do it, when volunteering. Yarimasu sounds keener, shimasu more measured; with clients, stay with shimasu or itashimasu.

Yatta! is the shout of delight when something works out, literally I did it. Yatte oku means to do something in advance so that it is ready. Yatteru asks whether a shop or event is on: mada yatteru? Is it still open?

Yatte miru and the -te forms of yaru

The -te form of yaru, yatte, joins with helper verbs to make a family of expressions that every learner needs. Yatte miru means to try something and see how it goes. It is the standard way to accept a task you are not sure you can manage, and yatte mimasu is polite enough for the office.

Yatte kureru asks someone to do something for you, and yatte ageru offers to do it for a friend or junior. Yatte shimau, yatchau in speech, means to get something done, or to do it by mistake, depending on tone. Suru has the same combinations, shite miru, shite kureru, shite shimau, and they are a touch more formal.

Compounds that take only suru

Here is the firmest line between the two verbs. Suru attaches directly to Sino-Japanese nouns and many loanwords to form compound verbs: benkyō suru, to study; setsumei suru, to explain; ryokō suru, to travel; kopī suru, to copy. In these compounds the noun and suru are one word, with no particle between them. Yaru can never take that slot. Benkyō yaru is wrong; benkyō o yaru, with the particle, is casual and fine.

Some compounds resist even the o-yaru version. Verbs describing abstract, mental or institutional actions sound odd with yaru: kekkon suru, to marry; sonzai suru, to exist; shinpai suru, to worry; kanshin suru, to be impressed. Yaru prefers actions with a physical or task-like feel, so shiai o yaru, to play a match, and ivento o yaru, to hold an event, are natural, while shinpai o yaru is not.

A rough test: if the noun is something you can picture yourself physically doing, such as a match, a job, a rehearsal or a party, o yaru is available in casual speech. If it names a state, a feeling or a formal procedure, stay with suru.

Yaru as give: juniors, pets and plants

The second life of yaru has nothing to do with doing. It belongs to the give-and-receive family alongside ageru, kureru and morau. Ageru is the neutral verb for giving to someone else. Yaru is the version used when the receiver is clearly lower in status or not a person at all: a younger sibling, a small child, a pet, a plant.

Water and food are the classic objects. Hana ni mizu o yaru, to water the flowers; inu ni esa o yaru, to feed the dog; neko ni oyatsu o yaru, to give the cat a treat. Many speakers today use ageru even for pets and plants, because yaru can sound brusque, and mizu o ageru is now common and perfectly acceptable. Yaru remains natural, especially in older speakers and in casual male speech, and you will hear it constantly.

With people, be careful. Otōto ni yaru, to give it to my younger brother, is normal inside a family. Using yaru towards a colleague, an equal or anyone older is rude. Ageru is always safe, and for giving to a superior you need sashiageru.

The rougher side of yaru

Yaru has an aggressive register that suru never has. In crime dramas and gangster films, yaru is the euphemism for killing or beating someone: yatta no wa dare da, who did it. In sport it means to beat an opponent. In arguments, yatte yaru, with the second yaru as a helper, means I'll show you, I'll do it out of spite. Yatchimae is a shout of go on, do it, from a crowd.

There is also a sexual slang sense in very casual speech. None of these meanings appear in polite conversation, but they explain why yaru feels edgier than suru and why it should stay out of formal settings.

• Yatte yaru: I'll do it, with defiance or spite
• Yatte yaru zo: watch me, I'll pull it off
• Aitsu o yaru: to get him, in fights or crime stories
• Zettai ni yarareta: we got thrashed, in sport or games

The passive yarareru is common and usually harmless: shiken de yarareta, the exam got me; kaze ni yarareta, a cold knocked me out. It expresses being beaten by something, and it is fine between friends.

Polite alternatives: nasaru and itasu

When the conversation turns polite, both verbs give way to the keigo pair nasaru and itasu. Nasaru is respectful, used for actions done by the person you are honouring: a customer, a client, a teacher, a guest. Its polite form is irregular, nasaimasu, and the -te form is nasatte. Dō nasaimasu ka means what would you like to do. In compounds it replaces suru: go-riyō nasaimasu ka, will you be using it.

Itasu is humble, used for your own actions or your company's. Watashi ga itashimasu, I will do it, and go-annai itashimasu, I will show you the way. Shite orimasu is the humble progressive. Learners often over-apply itasu to other people's actions, which is a clear mistake: only you and your side itasu.

Yaru has no keigo forms of its own, so when you need respect or humility, you switch verbs. Sensei ga yarimasu is fine in a relaxed classroom, but sensei ga nasaimasu is the correct respectful form.

Mistakes learners make with suru and yaru

The most common error is using yaru with people who deserve suru: a shop assistant, a teacher, a new acquaintance. Yaru itself is not vulgar, but the mismatch of register makes you sound careless. The fix is simple: default to shimasu, and let yaru into your speech only when the other person uses it first.

The second error is attaching yaru directly to a noun, benkyō yaru or renshū yaru. Add o, and remember that some nouns refuse yaru altogether. The third error is using yaru when giving something to a friend. Yaru downward, ageru sideways, sashiageru upward.

Finally, watch the give-and-do overlap. Mizu o yaru means to water, and otōto ni yaru means to give to my brother. The particle ni usually makes the meaning clear; if you want no ambiguity, use ageru for giving and keep yaru for doing.