Questions & Answers about Mi hermano es muy pesado cuando bromea todo el día.
Why does pesado mean annoying here if I learned that it means heavy?
Because pesado has both a literal and a figurative meaning.
- Literal: heavy
- Figurative (very common in Spain): annoying, tiresome, a pain
So in this sentence, Mi hermano es muy pesado does not mean that your brother is physically heavy. It means he is really annoying / tiresome, especially because of the behavior described after it.
This figurative use is extremely common in everyday Spanish in Spain.
Why is it es muy pesado and not está muy pesado?
Both can exist, but they suggest slightly different things.
- Es muy pesado = this is presented more as part of his behavior or character in that situation; it sounds more general or typical.
- Está muy pesado = he is being especially annoying right now or in this temporary moment.
In your sentence, es muy pesado cuando bromea todo el día sounds like a habitual pattern: whenever he spends all day joking around, he becomes very annoying.
A learner-friendly way to think about it:
- ser = more general description / recurring trait
- estar = more temporary state / how someone is acting at the moment
That said, in real conversation, natives may use either depending on what they want to emphasize.