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