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