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