ぶるAct or pose as
This suffix forms a verb meaning to act or present yourself as having a certain status or quality. It often suggests affectation, showing off, or a pose that the speaker views critically.
An adopted manner
The subject is normally a person or character who can adopt a recognizable manner. The point is not simply that the person has a quality: they behave as if they have it, or make that quality especially visible. This need not be a deliberate lie; the speaker may simply find the behavior affected or showy.
How the pose appears
The surrounding context usually makes clear what kind of image the person is presenting.
弟は最近、大人ぶるようになった。
My younger brother has recently started acting grown-up.
AnalyzeThis may describe affected behavior without implying serious deception.
彼は会議で専門家ぶって、断定的な話し方をする。
In meetings, he poses as an expert and speaks in an overly definite manner.
Analyze知らないなら、知ったかぶらないほうがいい。
If you do not know, you should not pretend that you do.
AnalyzeQuality, pose, or explicit pretense
ぶる focuses on an adopted manner and often carries criticism. By contrast, びる describes taking on a quality or appearance and does not require intentional performance. The broader expression ふりをする explicitly says that someone pretends to be or do something and can be used with a much wider range of actions and states.
More examples
母は私が大人ぶって話すたびに、笑いをこらえていた。
Whenever I tried to talk like a grown-up, my mother struggled not to laugh.
Analyze知ったかぶって答えるより、確認したほうがいい。
It is better to check than to answer while pretending you know.
Analyze彼は偉ぶらず、若い社員の意見にも耳を傾ける。
He does not act important and listens to younger employees as well.
Analyzeあの客は通ぶってワインを選んでいた。
That customer was choosing wine while posing as a connoisseur.
Analyze小説の主人公は紳士ぶった口調で話す。
The novel's main character speaks in an affectedly gentlemanly tone.
Analyze善人ぶるつもりはないが、困っている人を放っておけない。
I am not trying to play the saint, but I cannot ignore someone in trouble.
Analyze