could startle
Regular verb: startle - startled- startled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could startle
you could startle
he could startle
we could startle
you could startle
they could startle 	I could be startling
you could be startling
he could be startling
we could be startling
you could be startling
they could be startling	I could have startled
you could have startled
he could have startled
we could have startled
you could have startled
they could have startled	I could have been startling
you could have been startling
he could have been startling
we could have been startling
you could have been startling
they could have been startling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't startle
you couldn't startle
he couldn't startle
we couldn't startle
you couldn't startle
they couldn't startle 	I couldn't be startling
you couldn't be startling
he couldn't be startling
we couldn't be startling
you couldn't be startling
they couldn't be startling	I couldn't have startled
you couldn't have startled
he couldn't have startled
we couldn't have startled
you couldn't have startled
they couldn't have startled	I couldn't have been startling
you couldn't have been startling
he couldn't have been startling
we couldn't have been startling
you couldn't have been startling
they couldn't have been startling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I startle?
could you startle?
could he startle?
could we startle?
could you startle?
could they startle? 	could I be startling?
could you be startling?
could he be startling?
could we be startling?
could you be startling?
could they be startling? 	could I have startled?
could you have startled?
could he have startled?
could we have startled?
could you have startled?
could they have startled? 	could I have been startling?
could you have been startling?
could he have been startling?
could we have been startling?
could you have been startling?
could they have been startling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I startle?
couldn't you startle?
couldn't he startle?
couldn't we startle?
couldn't you startle?
couldn't they startle? 	couldn't I be startling?
couldn't you be startling?
couldn't he be startling?
couldn't we be startling?
couldn't you be startling?
couldn't they be startling? 	couldn't I have startled?
couldn't you have startled?
couldn't he have startled?
couldn't we have startled?
couldn't you have startled?
couldn't they have startled? 	couldn't I have been startling?
couldn't you have been startling?
couldn't he have been startling?
couldn't we have been startling?
couldn't you have been startling?
couldn't they have been startling?