を (cause of emotion)

• Reading: を
• Romaji: o
• Formation: Cause/Object + を + Emotion verb (悲しむ, 喜ぶ, 心配する, 怖がる, etc.)

Meaning

A particle that marks the cause or object of a human emotion. It indicates what triggers a feeling such as sadness, joy, fear, longing, or worry.

This lesser-known use of を connects an emotion with its cause. Common expressions include 別れを悲しむ (grieve a parting), 将来を心配する (worry about the future), 成功を喜ぶ (rejoice at success), and 暗闇を怖がる (fear the darkness). The emotion verbs involved are typically intransitive in English but function with を in Japanese because the emotion is directed at something. This pattern is more common in written Japanese and formal speech than in casual conversation. Learners often mistake this for a regular direct object, but the nuance is specifically that the noun causes or provokes the emotional response.

Examples

1. 母は息子の将来を心配している。 My mother is worried about her son's future.
2. 友人たちは彼の成功を喜んだ。 His friends celebrated his success.
3. 子供が暗闇を怖がっている。 The child is afraid of the dark.

Usage Guide

Context: written, spoken, formal

Tone: expressive

Do Say

• 彼は試験の結果を心配していた。
• 祖母は孫の成長を喜んでいます。
• 弟は犬を怖がります。

Don't Say

• 将来に心配しています。(Using に instead of を with 心配する for the object of worry) → 将来を心配しています。
• 暗闇が怖がっている。(Using が makes 暗闇 the subject, changing the meaning entirely) → 暗闇を怖がっている。

Origin & History

This emotive use of を reflects an older pattern where the particle marked the target of psychological direction. It is related to classical Japanese constructions where を governed the object of emotional or mental engagement.

Cultural Context

Generation: All ages

Social background: Universal