should filter
Regular verb: filter - filtered- filtered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should filter
you should filter
he should filter
we should filter
you should filter
they should filter 	I should be filtering
you should be filtering
he should be filtering
we should be filtering
you should be filtering
they should be filtering	I should have filtered
you should have filtered
he should have filtered
we should have filtered
you should have filtered
they should have filtered	I should have been filtering
you should have been filtering
he should have been filtering
we should have been filtering
you should have been filtering
they should have been filtering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not filter
you should not filter
he should not filter
we should not filter
you should not filter
they should not filter 	I should not be filtering
you should not be filtering
he should not be filtering
we should not be filtering
you should not be filtering
they should not be filtering	I should not have filtered
you should not have filtered
he should not have filtered
we should not have filtered
you should not have filtered
they should not have filtered	I should not have been filtering
you should not have been filtering
he should not have been filtering
we should not have been filtering
you should not have been filtering
they should not have been filtering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I filter?
should you filter?
should he filter?
should we filter?
should you filter?
should they filter? 	should I be filtering?
should you be filtering?
should he be filtering?
should we be filtering?
should you be filtering?
should they be filtering? 	should I have filtered?
should you have filtered?
should he have filtered?
should we have filtered?
should you have filtered?
should they have filtered? 	should I have been filtering?
should you have been filtering?
should he have been filtering?
should we have been filtering?
should you have been filtering?
should they have been filtering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not filter?
should you not filter?
should he not filter?
should we not filter?
should you not filter?
should they not filter? 	should I not be filtering?
should you not be filtering?
should he not be filtering?
should we not be filtering?
should you not be filtering?
should they not be filtering? 	should I not have filtered?
should you not have filtered?
should he not have filtered?
should we not have filtered?
should you not have filtered?
should they not have filtered? 	should I not have been filtering?
should you not have been filtering?
should he not have been filtering?
should we not have been filtering?
should you not have been filtering?
should they not have been filtering?