He can't come home after dark.
He's not allowed to come home after dark
We can walk on the grass here.
We're allowed to walk on the grass here.
She doesn't have to tidy up her room. Her mum says so.
Her mum doesn't make her tidy up her room.
I can stay up late to watch the match. My dad says so.
My dad lets me stay up late to watch the match
We have to ring her when we arrive. My mum says so.
My mum makes us ring her when we arrive.
Students can't use mobile phones in the classroom. Their teacher says so.
Students are not allowed to use their mobile phones in the classroom.