本気(ほんき)にする

ほんきにする
expression
to take seriously; to believe (something said in jest)
communication
1. to take seriously; to believe; to take at face value
To treat something said — often a joke, exaggeration, or casual remark — as if it were genuinely meant. Frequently used when someone mistakenly believes something that was not intended seriously.
冗談(じょうだん)を本気(ほんき)にするな。
Don't take the joke seriously.
彼(かれ)は私(わたし)の嘘(うそ)を本気(ほんき)にした。
He actually believed my lie.
適当(てきとう)に言(い)っただけなのに、本気(ほんき)にしないでよ。
I just said it offhandedly — don't take it seriously.

Composed of 本気(ほんき) (seriousness, earnestness) + にする (to treat as, to make into). The expression focuses on the listener's interpretation: treating something as serious or true.

Usage

Often used in the negative imperative 本気(ほんき)にするな / 本気(ほんき)にしないで (don't take it seriously). Distinct from 本気(ほんき)を出(だ)す (to get serious, to give it one's all), which is about one's own effort rather than interpreting someone else's words.

Common collocations

  • 冗談(じょうだん)を本気(ほんき)にする — to take a joke seriously
  • 本気(ほんき)にしないで — don't take it seriously
  • 本気(ほんき)にされる — to be taken seriously (passive)
  • 嘘(うそ)を本気(ほんき)にする — to believe a lie

Similar words

Related Words

Compare: 真(ま)に受(う)ける (to take at face value (very similar)
Compare: 信(しん)じる (to believe (neutral)
general
Added 2026.3.29 5:18 · Revised 2026.9.2 13:01
20000/20317_honkinisuru