I can blacken you can blacken he can blacken we can blacken you can blacken they can blacken
V-ing form
I can be blackening you can be blackening he can be blackening we can be blackening you can be blackening they can be blackening
Perfect
I can have blackened you can have blackened he can have blackened we can have blackened you can have blackened they can have blackened
V-ing perfect
I can have been blackening you can have been blackening he can have been blackening we can have been blackening you can have been blackening they can have been blackening
Negation
Simple form
I can't blacken you can't blacken he can't blacken we can't blacken you can't blacken they can't blacken
V-ing form
I can't be blackening you can't be blackening he can't be blackening we can't be blackening you can't be blackening they can't be blackening
Perfect
I can't have blackened you can't have blackened he can't have blackened we can't have blackened you can't have blackened they can't have blackened
V-ing perfect
I can't have been blackening you can't have been blackening he can't have been blackening we can't have been blackening you can't have been blackening they can't have been blackening
Interrogative form
Simple form
can I blacken? can you blacken? can he blacken? can we blacken? can you blacken? can they blacken?
V-ing form
can I be blackening? can you be blackening? can he be blackening? can we be blackening? can you be blackening? can they be blackening?
Perfect
can I have blackened? can you have blackened? can he have blackened? can we have blackened? can you have blackened? can they have blackened?
V-ing perfect
can I have been blackening? can you have been blackening? can he have been blackening? can we have been blackening? can you have been blackening? can they have been blackening?
Interro-negative form
Simple form
can't I blacken? can't you blacken? can't he blacken? can't we blacken? can't you blacken? can't they blacken?
V-ing form
can't I be blackening? can't you be blackening? can't he be blackening? can't we be blackening? can't you be blackening? can't they be blackening?
Perfect
can't I have blackened? can't you have blackened? can't he have blackened? can't we have blackened? can't you have blackened? can't they have blackened?
V-ing perfect
can't I have been blackening? can't you have been blackening? can't he have been blackening? can't we have been blackening? can't you have been blackening? can't they have been blackening?