Affected describes behavior or speech that seems artificial or overly dramatic, as if someone is putting on a performance instead of being genuine. When someone speaks with an affected accent they didn't grow up with, or uses fancy vocabulary to sound more impressive, others can usually tell something feels false or forced.

You might notice affected manners when someone suddenly starts acting very formal or sophisticated around certain people, like a classmate who normally speaks casually but uses elaborate words when talking to the principal. An affected laugh sounds rehearsed rather than spontaneous, like someone practicing how they think laughter should sound instead of just laughing.

The word captures that quality of trying too hard to seem a certain way. An affected style of writing uses unnecessarily complex sentences when simple ones would work better. Someone with an affected personality might constantly adjust how they act based on who's watching, never quite seeming like themselves.

While we all adjust our behavior somewhat in different situations, affected behavior crosses into pretense. It's the difference between being polite to a teacher and suddenly pretending you're someone you're not.