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