I can pierce you can pierce he can pierce we can pierce you can pierce they can pierce
V-ing form
I can be piercing you can be piercing he can be piercing we can be piercing you can be piercing they can be piercing
Perfect
I can have pierced you can have pierced he can have pierced we can have pierced you can have pierced they can have pierced
V-ing perfect
I can have been piercing you can have been piercing he can have been piercing we can have been piercing you can have been piercing they can have been piercing
Negation
Simple form
I cannot pierce you cannot pierce he cannot pierce we cannot pierce you cannot pierce they cannot pierce
V-ing form
I cannot be piercing you cannot be piercing he cannot be piercing we cannot be piercing you cannot be piercing they cannot be piercing
Perfect
I cannot have pierced you cannot have pierced he cannot have pierced we cannot have pierced you cannot have pierced they cannot have pierced
V-ing perfect
I cannot have been piercing you cannot have been piercing he cannot have been piercing we cannot have been piercing you cannot have been piercing they cannot have been piercing
Interrogative form
Simple form
can I pierce? can you pierce? can he pierce? can we pierce? can you pierce? can they pierce?
V-ing form
can I be piercing? can you be piercing? can he be piercing? can we be piercing? can you be piercing? can they be piercing?
Perfect
can I have pierced? can you have pierced? can he have pierced? can we have pierced? can you have pierced? can they have pierced?
V-ing perfect
can I have been piercing? can you have been piercing? can he have been piercing? can we have been piercing? can you have been piercing? can they have been piercing?
Interro-negative form
Simple form
can I not pierce? can you not pierce? can he not pierce? can we not pierce? can you not pierce? can they not pierce?
V-ing form
can I not be piercing? can you not be piercing? can he not be piercing? can we not be piercing? can you not be piercing? can they not be piercing?
Perfect
can I not have pierced? can you not have pierced? can he not have pierced? can we not have pierced? can you not have pierced? can they not have pierced?
V-ing perfect
can I not have been piercing? can you not have been piercing? can he not have been piercing? can we not have been piercing? can you not have been piercing? can they not have been piercing?