should mark
Regular verb: mark - marked- marked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I'd mark
you'd mark
she'd mark
we'd mark
you'd mark
they'd mark 	I'd be marking
you'd be marking
she'd be marking
we'd be marking
you'd be marking
they'd be marking	I should've marked
you should've marked
she should've marked
we should've marked
you should've marked
they should've marked	I should've been marking
you should've been marking
she should've been marking
we should've been marking
you should've been marking
they should've been marking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I shouldn't mark
you shouldn't mark
she shouldn't mark
we shouldn't mark
you shouldn't mark
they shouldn't mark 	I shouldn't be marking
you shouldn't be marking
she shouldn't be marking
we shouldn't be marking
you shouldn't be marking
they shouldn't be marking	I shouldn't have marked
you shouldn't have marked
she shouldn't have marked
we shouldn't have marked
you shouldn't have marked
they shouldn't have marked	I shouldn't have been marking
you shouldn't have been marking
she shouldn't have been marking
we shouldn't have been marking
you shouldn't have been marking
they shouldn't have been marking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I mark?
should you mark?
should she mark?
should we mark?
should you mark?
should they mark? 	should I be marking?
should you be marking?
should she be marking?
should we be marking?
should you be marking?
should they be marking? 	should I have marked?
should you have marked?
should she have marked?
should we have marked?
should you have marked?
should they have marked? 	should I have been marking?
should you have been marking?
should she have been marking?
should we have been marking?
should you have been marking?
should they have been marking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
shouldn't I mark?
shouldn't you mark?
shouldn't she mark?
shouldn't we mark?
shouldn't you mark?
shouldn't they mark? 	shouldn't I be marking?
shouldn't you be marking?
shouldn't she be marking?
shouldn't we be marking?
shouldn't you be marking?
shouldn't they be marking? 	shouldn't I have marked?
shouldn't you have marked?
shouldn't she have marked?
shouldn't we have marked?
shouldn't you have marked?
shouldn't they have marked? 	shouldn't I have been marking?
shouldn't you have been marking?
shouldn't she have been marking?
shouldn't we have been marking?
shouldn't you have been marking?
shouldn't they have been marking?