English verb conjugation
CAN INVESTIGATE

Regular verb: investigate - investigated - investigated

Affirmation

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

Negation

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

Interrogative form

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

Interro-negative form

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