I could aggrade you could aggrade he could aggrade we could aggrade you could aggrade they could aggrade
V-ing form
I could be aggrading you could be aggrading he could be aggrading we could be aggrading you could be aggrading they could be aggrading
Perfect
I could have aggraded you could have aggraded he could have aggraded we could have aggraded you could have aggraded they could have aggraded
V-ing perfect
I could have been aggrading you could have been aggrading he could have been aggrading we could have been aggrading you could have been aggrading they could have been aggrading
Negation
Simple form
I couldn't aggrade you couldn't aggrade he couldn't aggrade we couldn't aggrade you couldn't aggrade they couldn't aggrade
V-ing form
I couldn't be aggrading you couldn't be aggrading he couldn't be aggrading we couldn't be aggrading you couldn't be aggrading they couldn't be aggrading
Perfect
I couldn't have aggraded you couldn't have aggraded he couldn't have aggraded we couldn't have aggraded you couldn't have aggraded they couldn't have aggraded
V-ing perfect
I couldn't have been aggrading you couldn't have been aggrading he couldn't have been aggrading we couldn't have been aggrading you couldn't have been aggrading they couldn't have been aggrading
Interrogative form
Simple form
could I aggrade? could you aggrade? could he aggrade? could we aggrade? could you aggrade? could they aggrade?
V-ing form
could I be aggrading? could you be aggrading? could he be aggrading? could we be aggrading? could you be aggrading? could they be aggrading?
Perfect
could I have aggraded? could you have aggraded? could he have aggraded? could we have aggraded? could you have aggraded? could they have aggraded?
V-ing perfect
could I have been aggrading? could you have been aggrading? could he have been aggrading? could we have been aggrading? could you have been aggrading? could they have been aggrading?
Interro-negative form
Simple form
couldn't I aggrade? couldn't you aggrade? couldn't he aggrade? couldn't we aggrade? couldn't you aggrade? couldn't they aggrade?
V-ing form
couldn't I be aggrading? couldn't you be aggrading? couldn't he be aggrading? couldn't we be aggrading? couldn't you be aggrading? couldn't they be aggrading?
Perfect
couldn't I have aggraded? couldn't you have aggraded? couldn't he have aggraded? couldn't we have aggraded? couldn't you have aggraded? couldn't they have aggraded?
V-ing perfect
couldn't I have been aggrading? couldn't you have been aggrading? couldn't he have been aggrading? couldn't we have been aggrading? couldn't you have been aggrading? couldn't they have been aggrading?