English verb conjugation
SHOULD INVESTIGATE

Regular verb: investigate - investigated - investigated

Affirmation

Simple form	V-ing form
I should investigate you should investigate he should investigate we should investigate you should investigate they should investigate	I should be investigating you should be investigating he should be investigating we should be investigating you should be investigating they should be investigating
Perfect	V-ing perfect
I should have investigated you should have investigated he should have investigated we should have investigated you should have investigated they should have investigated	I should have been investigating you should have been investigating he should have been investigating we should have been investigating you should have been investigating they should have been investigating

Negation

Simple form	V-ing form
I should not investigate you should not investigate he should not investigate we should not investigate you should not investigate they should not investigate	I should not be investigating you should not be investigating he should not be investigating we should not be investigating you should not be investigating they should not be investigating
Perfect	V-ing perfect
I should not have investigated you should not have investigated he should not have investigated we should not have investigated you should not have investigated they should not have investigated	I should not have been investigating you should not have been investigating he should not have been investigating we should not have been investigating you should not have been investigating they should not have been investigating

Interrogative form

Simple form	V-ing form
should I investigate? should you investigate? should he investigate? should we investigate? should you investigate? should they investigate?	should I be investigating? should you be investigating? should he be investigating? should we be investigating? should you be investigating? should they be investigating?
Perfect	V-ing perfect
should I have investigated? should you have investigated? should he have investigated? should we have investigated? should you have investigated? should they have investigated?	should I have been investigating? should you have been investigating? should he have been investigating? should we have been investigating? should you have been investigating? should they have been investigating?

Interro-negative form

Simple form	V-ing form
should I not investigate? should you not investigate? should he not investigate? should we not investigate? should you not investigate? should they not investigate?	should I not be investigating? should you not be investigating? should he not be investigating? should we not be investigating? should you not be investigating? should they not be investigating?
Perfect	V-ing perfect
should I not have investigated? should you not have investigated? should he not have investigated? should we not have investigated? should you not have investigated? should they not have investigated?	should I not have been investigating? should you not have been investigating? should he not have been investigating? should we not have been investigating? should you not have been investigating? should they not have been investigating?