I can fulfill you can fulfill he can fulfill we can fulfill you can fulfill they can fulfill
V-ing form
I can be fulfilling you can be fulfilling he can be fulfilling we can be fulfilling you can be fulfilling they can be fulfilling
Perfect
I can have fulfilled you can have fulfilled he can have fulfilled we can have fulfilled you can have fulfilled they can have fulfilled
V-ing perfect
I can have been fulfilling you can have been fulfilling he can have been fulfilling we can have been fulfilling you can have been fulfilling they can have been fulfilling
Negation
Simple form
I can't fulfill you can't fulfill he can't fulfill we can't fulfill you can't fulfill they can't fulfill
V-ing form
I can't be fulfilling you can't be fulfilling he can't be fulfilling we can't be fulfilling you can't be fulfilling they can't be fulfilling
Perfect
I can't have fulfilled you can't have fulfilled he can't have fulfilled we can't have fulfilled you can't have fulfilled they can't have fulfilled
V-ing perfect
I can't have been fulfilling you can't have been fulfilling he can't have been fulfilling we can't have been fulfilling you can't have been fulfilling they can't have been fulfilling
Interrogative form
Simple form
can I fulfill? can you fulfill? can he fulfill? can we fulfill? can you fulfill? can they fulfill?
V-ing form
can I be fulfilling? can you be fulfilling? can he be fulfilling? can we be fulfilling? can you be fulfilling? can they be fulfilling?
Perfect
can I have fulfilled? can you have fulfilled? can he have fulfilled? can we have fulfilled? can you have fulfilled? can they have fulfilled?
V-ing perfect
can I have been fulfilling? can you have been fulfilling? can he have been fulfilling? can we have been fulfilling? can you have been fulfilling? can they have been fulfilling?
Interro-negative form
Simple form
can't I fulfill? can't you fulfill? can't he fulfill? can't we fulfill? can't you fulfill? can't they fulfill?
V-ing form
can't I be fulfilling? can't you be fulfilling? can't he be fulfilling? can't we be fulfilling? can't you be fulfilling? can't they be fulfilling?
Perfect
can't I have fulfilled? can't you have fulfilled? can't he have fulfilled? can't we have fulfilled? can't you have fulfilled? can't they have fulfilled?
V-ing perfect
can't I have been fulfilling? can't you have been fulfilling? can't he have been fulfilling? can't we have been fulfilling? can't you have been fulfilling? can't they have been fulfilling?