I can snowball you can snowball she can snowball we can snowball you can snowball they can snowball
V-ing form
I can be snowballing you can be snowballing she can be snowballing we can be snowballing you can be snowballing they can be snowballing
Perfect
I can have snowballed you can have snowballed she can have snowballed we can have snowballed you can have snowballed they can have snowballed
V-ing perfect
I can have been snowballing you can have been snowballing she can have been snowballing we can have been snowballing you can have been snowballing they can have been snowballing
Negation
Simple form
I cannot snowball you cannot snowball she cannot snowball we cannot snowball you cannot snowball they cannot snowball
V-ing form
I cannot be snowballing you cannot be snowballing she cannot be snowballing we cannot be snowballing you cannot be snowballing they cannot be snowballing
Perfect
I cannot have snowballed you cannot have snowballed she cannot have snowballed we cannot have snowballed you cannot have snowballed they cannot have snowballed
V-ing perfect
I cannot have been snowballing you cannot have been snowballing she cannot have been snowballing we cannot have been snowballing you cannot have been snowballing they cannot have been snowballing
Interrogative form
Simple form
can I snowball? can you snowball? can she snowball? can we snowball? can you snowball? can they snowball?
V-ing form
can I be snowballing? can you be snowballing? can she be snowballing? can we be snowballing? can you be snowballing? can they be snowballing?
Perfect
can I have snowballed? can you have snowballed? can she have snowballed? can we have snowballed? can you have snowballed? can they have snowballed?
V-ing perfect
can I have been snowballing? can you have been snowballing? can she have been snowballing? can we have been snowballing? can you have been snowballing? can they have been snowballing?
Interro-negative form
Simple form
can I not snowball? can you not snowball? can she not snowball? can we not snowball? can you not snowball? can they not snowball?
V-ing form
can I not be snowballing? can you not be snowballing? can she not be snowballing? can we not be snowballing? can you not be snowballing? can they not be snowballing?
Perfect
can I not have snowballed? can you not have snowballed? can she not have snowballed? can we not have snowballed? can you not have snowballed? can they not have snowballed?
V-ing perfect
can I not have been snowballing? can you not have been snowballing? can she not have been snowballing? can we not have been snowballing? can you not have been snowballing? can they not have been snowballing?