English verb conjugation
CAN POSTMARK

Regular verb: postmark - postmarked - postmarked

Affirmation

Simple form	V-ing form
I can postmark you can postmark he can postmark we can postmark you can postmark they can postmark	I can be postmarking you can be postmarking he can be postmarking we can be postmarking you can be postmarking they can be postmarking
Perfect	V-ing perfect
I can have postmarked you can have postmarked he can have postmarked we can have postmarked you can have postmarked they can have postmarked	I can have been postmarking you can have been postmarking he can have been postmarking we can have been postmarking you can have been postmarking they can have been postmarking

Negation

Simple form	V-ing form
I cannot postmark you cannot postmark he cannot postmark we cannot postmark you cannot postmark they cannot postmark	I cannot be postmarking you cannot be postmarking he cannot be postmarking we cannot be postmarking you cannot be postmarking they cannot be postmarking
Perfect	V-ing perfect
I cannot have postmarked you cannot have postmarked he cannot have postmarked we cannot have postmarked you cannot have postmarked they cannot have postmarked	I cannot have been postmarking you cannot have been postmarking he cannot have been postmarking we cannot have been postmarking you cannot have been postmarking they cannot have been postmarking

Interrogative form

Simple form	V-ing form
can I postmark? can you postmark? can he postmark? can we postmark? can you postmark? can they postmark?	can I be postmarking? can you be postmarking? can he be postmarking? can we be postmarking? can you be postmarking? can they be postmarking?
Perfect	V-ing perfect
can I have postmarked? can you have postmarked? can he have postmarked? can we have postmarked? can you have postmarked? can they have postmarked?	can I have been postmarking? can you have been postmarking? can he have been postmarking? can we have been postmarking? can you have been postmarking? can they have been postmarking?

Interro-negative form

Simple form	V-ing form
can I not postmark? can you not postmark? can he not postmark? can we not postmark? can you not postmark? can they not postmark?	can I not be postmarking? can you not be postmarking? can he not be postmarking? can we not be postmarking? can you not be postmarking? can they not be postmarking?
Perfect	V-ing perfect
can I not have postmarked? can you not have postmarked? can he not have postmarked? can we not have postmarked? can you not have postmarked? can they not have postmarked?	can I not have been postmarking? can you not have been postmarking? can he not have been postmarking? can we not have been postmarking? can you not have been postmarking? can they not have been postmarking?