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