should preinvestigate
Regular verb: preinvestigate - preinvestigated- preinvestigated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should preinvestigate
you should preinvestigate
he should preinvestigate
we should preinvestigate
you should preinvestigate
they should preinvestigate 	I should be preinvestigating
you should be preinvestigating
he should be preinvestigating
we should be preinvestigating
you should be preinvestigating
they should be preinvestigating	I should have preinvestigated
you should have preinvestigated
he should have preinvestigated
we should have preinvestigated
you should have preinvestigated
they should have preinvestigated	I should have been preinvestigating
you should have been preinvestigating
he should have been preinvestigating
we should have been preinvestigating
you should have been preinvestigating
they should have been preinvestigating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I should not preinvestigate
you should not preinvestigate
he should not preinvestigate
we should not preinvestigate
you should not preinvestigate
they should not preinvestigate 	I should not be preinvestigating
you should not be preinvestigating
he should not be preinvestigating
we should not be preinvestigating
you should not be preinvestigating
they should not be preinvestigating	I should not have preinvestigated
you should not have preinvestigated
he should not have preinvestigated
we should not have preinvestigated
you should not have preinvestigated
they should not have preinvestigated	I should not have been preinvestigating
you should not have been preinvestigating
he should not have been preinvestigating
we should not have been preinvestigating
you should not have been preinvestigating
they should not have been preinvestigating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I preinvestigate?
should you preinvestigate?
should he preinvestigate?
should we preinvestigate?
should you preinvestigate?
should they preinvestigate? 	should I be preinvestigating?
should you be preinvestigating?
should he be preinvestigating?
should we be preinvestigating?
should you be preinvestigating?
should they be preinvestigating? 	should I have preinvestigated?
should you have preinvestigated?
should he have preinvestigated?
should we have preinvestigated?
should you have preinvestigated?
should they have preinvestigated? 	should I have been preinvestigating?
should you have been preinvestigating?
should he have been preinvestigating?
should we have been preinvestigating?
should you have been preinvestigating?
should they have been preinvestigating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
should I not preinvestigate?
should you not preinvestigate?
should he not preinvestigate?
should we not preinvestigate?
should you not preinvestigate?
should they not preinvestigate? 	should I not be preinvestigating?
should you not be preinvestigating?
should he not be preinvestigating?
should we not be preinvestigating?
should you not be preinvestigating?
should they not be preinvestigating? 	should I not have preinvestigated?
should you not have preinvestigated?
should he not have preinvestigated?
should we not have preinvestigated?
should you not have preinvestigated?
should they not have preinvestigated? 	should I not have been preinvestigating?
should you not have been preinvestigating?
should he not have been preinvestigating?
should we not have been preinvestigating?
should you not have been preinvestigating?
should they not have been preinvestigating?