I can billow you can billow he can billow we can billow you can billow they can billow
V-ing form
I can be billowing you can be billowing he can be billowing we can be billowing you can be billowing they can be billowing
Perfect
I can have billowed you can have billowed he can have billowed we can have billowed you can have billowed they can have billowed
V-ing perfect
I can have been billowing you can have been billowing he can have been billowing we can have been billowing you can have been billowing they can have been billowing
Negation
Simple form
I can't billow you can't billow he can't billow we can't billow you can't billow they can't billow
V-ing form
I can't be billowing you can't be billowing he can't be billowing we can't be billowing you can't be billowing they can't be billowing
Perfect
I can't have billowed you can't have billowed he can't have billowed we can't have billowed you can't have billowed they can't have billowed
V-ing perfect
I can't have been billowing you can't have been billowing he can't have been billowing we can't have been billowing you can't have been billowing they can't have been billowing
Interrogative form
Simple form
can I billow? can you billow? can he billow? can we billow? can you billow? can they billow?
V-ing form
can I be billowing? can you be billowing? can he be billowing? can we be billowing? can you be billowing? can they be billowing?
Perfect
can I have billowed? can you have billowed? can he have billowed? can we have billowed? can you have billowed? can they have billowed?
V-ing perfect
can I have been billowing? can you have been billowing? can he have been billowing? can we have been billowing? can you have been billowing? can they have been billowing?
Interro-negative form
Simple form
can't I billow? can't you billow? can't he billow? can't we billow? can't you billow? can't they billow?
V-ing form
can't I be billowing? can't you be billowing? can't he be billowing? can't we be billowing? can't you be billowing? can't they be billowing?
Perfect
can't I have billowed? can't you have billowed? can't he have billowed? can't we have billowed? can't you have billowed? can't they have billowed?
V-ing perfect
can't I have been billowing? can't you have been billowing? can't he have been billowing? can't we have been billowing? can't you have been billowing? can't they have been billowing?