I can windmill you can windmill he can windmill we can windmill you can windmill they can windmill
V-ing form
I can be windmilling you can be windmilling he can be windmilling we can be windmilling you can be windmilling they can be windmilling
Perfect
I can have windmilled you can have windmilled he can have windmilled we can have windmilled you can have windmilled they can have windmilled
V-ing perfect
I can have been windmilling you can have been windmilling he can have been windmilling we can have been windmilling you can have been windmilling they can have been windmilling
Negation
Simple form
I can't windmill you can't windmill he can't windmill we can't windmill you can't windmill they can't windmill
V-ing form
I can't be windmilling you can't be windmilling he can't be windmilling we can't be windmilling you can't be windmilling they can't be windmilling
Perfect
I can't have windmilled you can't have windmilled he can't have windmilled we can't have windmilled you can't have windmilled they can't have windmilled
V-ing perfect
I can't have been windmilling you can't have been windmilling he can't have been windmilling we can't have been windmilling you can't have been windmilling they can't have been windmilling
Interrogative form
Simple form
can I windmill? can you windmill? can he windmill? can we windmill? can you windmill? can they windmill?
V-ing form
can I be windmilling? can you be windmilling? can he be windmilling? can we be windmilling? can you be windmilling? can they be windmilling?
Perfect
can I have windmilled? can you have windmilled? can he have windmilled? can we have windmilled? can you have windmilled? can they have windmilled?
V-ing perfect
can I have been windmilling? can you have been windmilling? can he have been windmilling? can we have been windmilling? can you have been windmilling? can they have been windmilling?
Interro-negative form
Simple form
can't I windmill? can't you windmill? can't he windmill? can't we windmill? can't you windmill? can't they windmill?
V-ing form
can't I be windmilling? can't you be windmilling? can't he be windmilling? can't we be windmilling? can't you be windmilling? can't they be windmilling?
Perfect
can't I have windmilled? can't you have windmilled? can't he have windmilled? can't we have windmilled? can't you have windmilled? can't they have windmilled?
V-ing perfect
can't I have been windmilling? can't you have been windmilling? can't he have been windmilling? can't we have been windmilling? can't you have been windmilling? can't they have been windmilling?