I can excavate you can excavate he can excavate we can excavate you can excavate they can excavate
V-ing form
I can be excavating you can be excavating he can be excavating we can be excavating you can be excavating they can be excavating
Perfect
I can have excavated you can have excavated he can have excavated we can have excavated you can have excavated they can have excavated
V-ing perfect
I can have been excavating you can have been excavating he can have been excavating we can have been excavating you can have been excavating they can have been excavating
Negation
Simple form
I cannot excavate you cannot excavate he cannot excavate we cannot excavate you cannot excavate they cannot excavate
V-ing form
I cannot be excavating you cannot be excavating he cannot be excavating we cannot be excavating you cannot be excavating they cannot be excavating
Perfect
I cannot have excavated you cannot have excavated he cannot have excavated we cannot have excavated you cannot have excavated they cannot have excavated
V-ing perfect
I cannot have been excavating you cannot have been excavating he cannot have been excavating we cannot have been excavating you cannot have been excavating they cannot have been excavating
Interrogative form
Simple form
can I excavate? can you excavate? can he excavate? can we excavate? can you excavate? can they excavate?
V-ing form
can I be excavating? can you be excavating? can he be excavating? can we be excavating? can you be excavating? can they be excavating?
Perfect
can I have excavated? can you have excavated? can he have excavated? can we have excavated? can you have excavated? can they have excavated?
V-ing perfect
can I have been excavating? can you have been excavating? can he have been excavating? can we have been excavating? can you have been excavating? can they have been excavating?
Interro-negative form
Simple form
can I not excavate? can you not excavate? can he not excavate? can we not excavate? can you not excavate? can they not excavate?
V-ing form
can I not be excavating? can you not be excavating? can he not be excavating? can we not be excavating? can you not be excavating? can they not be excavating?
Perfect
can I not have excavated? can you not have excavated? can he not have excavated? can we not have excavated? can you not have excavated? can they not have excavated?
V-ing perfect
can I not have been excavating? can you not have been excavating? can he not have been excavating? can we not have been excavating? can you not have been excavating? can they not have been excavating?