やる

やる is one of the most common verbs in casual Japanese, with two distinct meanings.

Transitivity

• Type: 他動詞(たどうし) (transitive)

SENSE 1 — TO DO (casual する):

• 仕事(しごと)をやる: to do work
• 宿題(しゅくだい)をやる: to do homework
• やってみる: to give it a try
• やり直(なお)す: to redo
• やり遂(と)げる: to accomplish, to see through
• 店(みせ)をやっている: to run a shop
• 一杯(いっぱい)やる: to have a drink

SENSE 2 — TO GIVE (downward):
Used for giving to animals, plants, or those of lower status:

• 犬(いぬ)に餌(えさ)をやる: to feed the dog
• 花(はな)に水(みず)をやる: to water the flowers
• 弟(おとうと)に小遣(こづか)いをやる: to give one's younger brother pocket money

With people, sense 2 sounds blunt and can be rude if the listener is not clearly a social inferior or a close family junior. Many speakers now prefer あげる even for children and pets.

Common patterns

• 〜てやる: to do something for someone below you (弟(おとうと)に宿題(しゅくだい)を教(おし)えてやる); also defiant resolve (絶対(ぜったい)に勝(か)ってやる! "I'll win, just watch!")

SIMILAR WORDS (giving verbs):

• やる: give (to animals/plants/inferiors — casual)
• あげる: give (to equals — standard; now also common for children and pets)
• 差(さ)し上(あ)げる: give (to superiors — humble/polite)

Register

やる (sense 1) is informal. In formal contexts, use する instead.