I could downgrade you could downgrade she could downgrade we could downgrade you could downgrade they could downgrade
V-ing form
I could be downgrading you could be downgrading she could be downgrading we could be downgrading you could be downgrading they could be downgrading
Perfect
I could have downgraded you could have downgraded she could have downgraded we could have downgraded you could have downgraded they could have downgraded
V-ing perfect
I could have been downgrading you could have been downgrading she could have been downgrading we could have been downgrading you could have been downgrading they could have been downgrading
Negation
Simple form
I couldn't downgrade you couldn't downgrade she couldn't downgrade we couldn't downgrade you couldn't downgrade they couldn't downgrade
V-ing form
I couldn't be downgrading you couldn't be downgrading she couldn't be downgrading we couldn't be downgrading you couldn't be downgrading they couldn't be downgrading
Perfect
I couldn't have downgraded you couldn't have downgraded she couldn't have downgraded we couldn't have downgraded you couldn't have downgraded they couldn't have downgraded
V-ing perfect
I couldn't have been downgrading you couldn't have been downgrading she couldn't have been downgrading we couldn't have been downgrading you couldn't have been downgrading they couldn't have been downgrading
Interrogative form
Simple form
could I downgrade? could you downgrade? could she downgrade? could we downgrade? could you downgrade? could they downgrade?
V-ing form
could I be downgrading? could you be downgrading? could she be downgrading? could we be downgrading? could you be downgrading? could they be downgrading?
Perfect
could I have downgraded? could you have downgraded? could she have downgraded? could we have downgraded? could you have downgraded? could they have downgraded?
V-ing perfect
could I have been downgrading? could you have been downgrading? could she have been downgrading? could we have been downgrading? could you have been downgrading? could they have been downgrading?
Interro-negative form
Simple form
couldn't I downgrade? couldn't you downgrade? couldn't she downgrade? couldn't we downgrade? couldn't you downgrade? couldn't they downgrade?
V-ing form
couldn't I be downgrading? couldn't you be downgrading? couldn't she be downgrading? couldn't we be downgrading? couldn't you be downgrading? couldn't they be downgrading?
Perfect
couldn't I have downgraded? couldn't you have downgraded? couldn't she have downgraded? couldn't we have downgraded? couldn't you have downgraded? couldn't they have downgraded?
V-ing perfect
couldn't I have been downgrading? couldn't you have been downgrading? couldn't she have been downgrading? couldn't we have been downgrading? couldn't you have been downgrading? couldn't they have been downgrading?