What is the Equivalent of Adding -er to a verb to make it "One who does x"?

Question

In English, to make a verb into "someone or something that does x" we add -er to the verb. Examples:

• crush → crusher
• teach → teacher
• run → runner
• spin → spinner

Is there a similar rule or pattern in Japanese?

Answer 1

Some kanji suffixes can be used for this.

Probably the most generic and closest to -er is -者{しゃ}：

• 医{い}者{しゃ} (doctor, physician)
• 歯{は}医{い}者{しゃ} (dentist)
• 忍{にん}者{じゃ} (ninja)
• 責任者{せきにんしゃ} (person responsible/in charge)
• 関係者{かんけいしゃ} (authorized person, staff)
• 科学者{かがくしゃ} (scientist)
• 通訳者{つうやくしゃ} (interpreter)

More such words (Wiktionary link)

NB: in some compounds 者 is read as もの, e.g. 若{わか}者{もの}, 馬鹿{ばか}者{もの}, 愚{おろ}か者{もの}.

Other common suffixes:

-屋{や}　(usually, but not always used for occupations with a [work]shop)

• 八{や}百{お}屋{や} (greengrocer)
• 肉{にく}屋{や} (butcher)
• 床{とこ}屋{や} (barber)
• 大{おお}屋{や} (landlord/landlady)
• 酒屋{さかや} (sake dealer/brewer)
• 質屋{しちや} (pawnbroker)
• 殺{ころ}し屋{や} (professional killer/hitman)

-家{か} can be used for professions usually(but not always) related to creativity:

• 漫画家【まんがか】 (mangaka, manga/comic writer)
• 画家 【がか】 (painter)
• 作家【さっか】 (writer/author)
• 小説家【しょうせつか】 (novelist, fiction writer)
• 作詞家【さくしか】 (lyricist, songwriter)
• 芸術家【げいじゅつか】 (artist (in entertainment industry))
• 評論家【ひょうろんか】 (critic)
• 農家 【のうか】 (farmer/plant grower)
• 実業家【じつぎょうか】 (businessman)

yet another suffix is -手{しゅ}:

• 歌手{かしゅ} - singer
• 選手{せんしゅ} - sportsman
• 運転手{うんてんしゅ} - driver/chauffeur
• 投手{とうしゅ} - baseball pitcher
• 騎手{きしゅ} - horseman/rider

NB: this suffix has been repurposed by Niconico Video users to refer to amateur artists posting videos of their performances. They use the same 手 kanji but with the て (kun) reading:

-歌{うた}い手{て} (utaite, amateur singer) from 歌手{かしゅ} (singer) -踊{おど}り手{て} (odorite, amateur dancer) from 踊{おど}る (dance)

in a few rare cases this suffix is also read -て in common words as well (thanks to @EiríkrÚtlendi):

• 買手【かいて】 (buyer/purchaser)
• 選【えら】び手【て】(selector/chooser)
• 使【つか】い手【て】(user of smth.)

Answer 2

For sino-Japanese nouns that can also be used as verbs (aka suru-verbs), adding 者 will work, as other answers explain.

For native Japanese verbs (aka yamato kotoba verbs), using masu-stem alone will often means "<verb> + er":

• のぞき peeper
• 酔っ払い drunkard
• すり pickpocket (from 掏る)
• 大食い big eater
• 人殺し murderer
• ピアノ弾き piano player
• 魔法使い (lit. "magic user") wizard

However these are nouns which have been fossilized long ago, and coining a new noun using this rule is generally not recommended.

Answer 3

I can only think of verb + 人/する人.

Your examples could be:

潰す人、教える人、走る人、回す人

Although, there can be a specific word for certain cases such as 先生 for 教える人 in the above.

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Another interesting example borrows from English's "-er" concept.

People who like the brand しまむら (shimamura) can be called しまラー (shima-er) and in the same way:

シャネル (chanel) -> シャネラー

安室奈美恵 (Namie Amuro, a singer) -> アムラー

NOTE: None of these are grammatical and are just slang words.

Answer 4

There is no strictly equivalent construct, although 〇〇する[者]{もの} (or 〇〇する人, 〇〇するの) will often serve.

Aside from that, especially when you have two-kanji Sino-japanese △△するcompounds, a related word on the form of △△[者]{しゃ} or △△さん will sometimes exist.

Answer 5

There are probably more, but these are two ways I could think of turning verbs to nouns:

Some words are formed by adding 手:
買い手
売り手
貸し手
借り手
聞き手
送り手

Some words are formed by adding 主:
買い主
売り主
飼い主