could investigate
Verbo regolare: investigate - investigated- investigated

Affermazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I could investigate
you could investigate
he could investigate
we could investigate
you could investigate
they could investigate 	I could be investigating
you could be investigating
he could be investigating
we could be investigating
you could be investigating
they could be investigating	I could have investigated
you could have investigated
he could have investigated
we could have investigated
you could have investigated
they could have investigated	I could have been investigating
you could have been investigating
he could have been investigating
we could have been investigating
you could have been investigating
they could have been investigating	

Negazione 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
I couldn't investigate
you couldn't investigate
he couldn't investigate
we couldn't investigate
you couldn't investigate
they couldn't investigate 	I couldn't be investigating
you couldn't be investigating
he couldn't be investigating
we couldn't be investigating
you couldn't be investigating
they couldn't be investigating	I couldn't have investigated
you couldn't have investigated
he couldn't have investigated
we couldn't have investigated
you couldn't have investigated
they couldn't have investigated	I couldn't have been investigating
you couldn't have been investigating
he couldn't have been investigating
we couldn't have been investigating
you couldn't have been investigating
they couldn't have been investigating	

Forma interrogativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
could I investigate?
could you investigate?
could he investigate?
could we investigate?
could you investigate?
could they investigate? 	could I be investigating?
could you be investigating?
could he be investigating?
could we be investigating?
could you be investigating?
could they be investigating? 	could I have investigated?
could you have investigated?
could he have investigated?
could we have investigated?
could you have investigated?
could they have investigated? 	could I have been investigating?
could you have been investigating?
could he have been investigating?
could we have been investigating?
could you have been investigating?
could they have been investigating? 	

Forma interro-negativa 	
Forma semplice 	Forma con V-ing 	Perfetto 	Perfetto con V-ing 	
couldn't I investigate?
couldn't you investigate?
couldn't he investigate?
couldn't we investigate?
couldn't you investigate?
couldn't they investigate? 	couldn't I be investigating?
couldn't you be investigating?
couldn't he be investigating?
couldn't we be investigating?
couldn't you be investigating?
couldn't they be investigating? 	couldn't I have investigated?
couldn't you have investigated?
couldn't he have investigated?
couldn't we have investigated?
couldn't you have investigated?
couldn't they have investigated? 	couldn't I have been investigating?
couldn't you have been investigating?
couldn't he have been investigating?
couldn't we have been investigating?
couldn't you have been investigating?
couldn't they have been investigating?