I can green you can green he can green we can green you can green they can green
V-ing form
I can be greening you can be greening he can be greening we can be greening you can be greening they can be greening
Perfect
I can have greened you can have greened he can have greened we can have greened you can have greened they can have greened
V-ing perfect
I can have been greening you can have been greening he can have been greening we can have been greening you can have been greening they can have been greening
Negation
Simple form
I can't green you can't green he can't green we can't green you can't green they can't green
V-ing form
I can't be greening you can't be greening he can't be greening we can't be greening you can't be greening they can't be greening
Perfect
I can't have greened you can't have greened he can't have greened we can't have greened you can't have greened they can't have greened
V-ing perfect
I can't have been greening you can't have been greening he can't have been greening we can't have been greening you can't have been greening they can't have been greening
Interrogative form
Simple form
can I green? can you green? can he green? can we green? can you green? can they green?
V-ing form
can I be greening? can you be greening? can he be greening? can we be greening? can you be greening? can they be greening?
Perfect
can I have greened? can you have greened? can he have greened? can we have greened? can you have greened? can they have greened?
V-ing perfect
can I have been greening? can you have been greening? can he have been greening? can we have been greening? can you have been greening? can they have been greening?
Interro-negative form
Simple form
can't I green? can't you green? can't he green? can't we green? can't you green? can't they green?
V-ing form
can't I be greening? can't you be greening? can't he be greening? can't we be greening? can't you be greening? can't they be greening?
Perfect
can't I have greened? can't you have greened? can't he have greened? can't we have greened? can't you have greened? can't they have greened?
V-ing perfect
can't I have been greening? can't you have been greening? can't he have been greening? can't we have been greening? can't you have been greening? can't they have been greening?