Use 'at heart' to express someone's true nature regardless of outward behavior.

True Nature

'At heart' often contrasts with a person's behavior or role that might suggest otherwise.

Contrasting Appearance

It underlines the core belief or inclination inside a person, sometimes hidden.

Reflects what someone truly desires or prefers, not always obvious in their current life.

Talks about emotions or feelings people carry inside, even if not expressed outwardly.

Can relate to where someone feels they belong culturally or geographically.

Use when appearances change but fundamental character or essence does not.

'At heart' highlights unchanging core values despite different circumstances.