could shuttle
Regular verb: shuttle - shuttled- shuttled

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could shuttle
you could shuttle
he could shuttle
we could shuttle
you could shuttle
they could shuttle 	I could be shuttling
you could be shuttling
he could be shuttling
we could be shuttling
you could be shuttling
they could be shuttling	I could have shuttled
you could have shuttled
he could have shuttled
we could have shuttled
you could have shuttled
they could have shuttled	I could have been shuttling
you could have been shuttling
he could have been shuttling
we could have been shuttling
you could have been shuttling
they could have been shuttling	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't shuttle
you couldn't shuttle
he couldn't shuttle
we couldn't shuttle
you couldn't shuttle
they couldn't shuttle 	I couldn't be shuttling
you couldn't be shuttling
he couldn't be shuttling
we couldn't be shuttling
you couldn't be shuttling
they couldn't be shuttling	I couldn't have shuttled
you couldn't have shuttled
he couldn't have shuttled
we couldn't have shuttled
you couldn't have shuttled
they couldn't have shuttled	I couldn't have been shuttling
you couldn't have been shuttling
he couldn't have been shuttling
we couldn't have been shuttling
you couldn't have been shuttling
they couldn't have been shuttling	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I shuttle?
could you shuttle?
could he shuttle?
could we shuttle?
could you shuttle?
could they shuttle? 	could I be shuttling?
could you be shuttling?
could he be shuttling?
could we be shuttling?
could you be shuttling?
could they be shuttling? 	could I have shuttled?
could you have shuttled?
could he have shuttled?
could we have shuttled?
could you have shuttled?
could they have shuttled? 	could I have been shuttling?
could you have been shuttling?
could he have been shuttling?
could we have been shuttling?
could you have been shuttling?
could they have been shuttling? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I shuttle?
couldn't you shuttle?
couldn't he shuttle?
couldn't we shuttle?
couldn't you shuttle?
couldn't they shuttle? 	couldn't I be shuttling?
couldn't you be shuttling?
couldn't he be shuttling?
couldn't we be shuttling?
couldn't you be shuttling?
couldn't they be shuttling? 	couldn't I have shuttled?
couldn't you have shuttled?
couldn't he have shuttled?
couldn't we have shuttled?
couldn't you have shuttled?
couldn't they have shuttled? 	couldn't I have been shuttling?
couldn't you have been shuttling?
couldn't he have been shuttling?
couldn't we have been shuttling?
couldn't you have been shuttling?
couldn't they have been shuttling?