I can stamp you can stamp he can stamp we can stamp you can stamp they can stamp
V-ing form
I can be stamping you can be stamping he can be stamping we can be stamping you can be stamping they can be stamping
Perfect
I can have stamped you can have stamped he can have stamped we can have stamped you can have stamped they can have stamped
V-ing perfect
I can have been stamping you can have been stamping he can have been stamping we can have been stamping you can have been stamping they can have been stamping
Negation
Simple form
I cannot stamp you cannot stamp he cannot stamp we cannot stamp you cannot stamp they cannot stamp
V-ing form
I cannot be stamping you cannot be stamping he cannot be stamping we cannot be stamping you cannot be stamping they cannot be stamping
Perfect
I cannot have stamped you cannot have stamped he cannot have stamped we cannot have stamped you cannot have stamped they cannot have stamped
V-ing perfect
I cannot have been stamping you cannot have been stamping he cannot have been stamping we cannot have been stamping you cannot have been stamping they cannot have been stamping
Interrogative form
Simple form
can I stamp? can you stamp? can he stamp? can we stamp? can you stamp? can they stamp?
V-ing form
can I be stamping? can you be stamping? can he be stamping? can we be stamping? can you be stamping? can they be stamping?
Perfect
can I have stamped? can you have stamped? can he have stamped? can we have stamped? can you have stamped? can they have stamped?
V-ing perfect
can I have been stamping? can you have been stamping? can he have been stamping? can we have been stamping? can you have been stamping? can they have been stamping?
Interro-negative form
Simple form
can I not stamp? can you not stamp? can he not stamp? can we not stamp? can you not stamp? can they not stamp?
V-ing form
can I not be stamping? can you not be stamping? can he not be stamping? can we not be stamping? can you not be stamping? can they not be stamping?
Perfect
can I not have stamped? can you not have stamped? can he not have stamped? can we not have stamped? can you not have stamped? can they not have stamped?
V-ing perfect
can I not have been stamping? can you not have been stamping? can he not have been stamping? can we not have been stamping? can you not have been stamping? can they not have been stamping?