Richard
2018.07.15 11:12
It might be useful to explain why they are used interchangeably.
Many things, possibly most things, can satisfy the conditions for both wide and broad.
A river for example can be wide or broad. From bank to bank it is wide, but the body of the river is broad. Therefore it satisfies both wide and broad.
A room, a boat or an aeroplane is the same, the floor is broad, the walls (or sides) are wide.
So they end up being used interchangeably.
But sometimes you would sound weird if you used them interchangeably.
Shoulders for example, would always be broad, never wide. You wouldn’t say “he has wide shoulders”, you’d say he has “broad shoulders”.
Hopefully this helps.