Use 'so what?' to show you don't care about something or it doesn't bother you.

Indifference

Often used informally among friends or in casual conversations.

Conversational Tone

Can be perceived as rude or dismissive if not used carefully.

Use it to prompt someone to justify their statement or claim.

Shows you question the importance or relevance of the information given.

Prompts further thought or discussion about a statement's significance.

Indicates skepticism or disbelief about what is being said.

It can imply that you suspect someone is not being completely honest.

Can carry a cynical tone, casting doubt on a situation's positive aspects.