could twitter
Regular verb: twitter - twittered- twittered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could twitter
you could twitter
he could twitter
we could twitter
you could twitter
they could twitter 	I could be twittering
you could be twittering
he could be twittering
we could be twittering
you could be twittering
they could be twittering	I could have twittered
you could have twittered
he could have twittered
we could have twittered
you could have twittered
they could have twittered	I could have been twittering
you could have been twittering
he could have been twittering
we could have been twittering
you could have been twittering
they could have been twittering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't twitter
you couldn't twitter
he couldn't twitter
we couldn't twitter
you couldn't twitter
they couldn't twitter 	I couldn't be twittering
you couldn't be twittering
he couldn't be twittering
we couldn't be twittering
you couldn't be twittering
they couldn't be twittering	I couldn't have twittered
you couldn't have twittered
he couldn't have twittered
we couldn't have twittered
you couldn't have twittered
they couldn't have twittered	I couldn't have been twittering
you couldn't have been twittering
he couldn't have been twittering
we couldn't have been twittering
you couldn't have been twittering
they couldn't have been twittering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I twitter?
could you twitter?
could he twitter?
could we twitter?
could you twitter?
could they twitter? 	could I be twittering?
could you be twittering?
could he be twittering?
could we be twittering?
could you be twittering?
could they be twittering? 	could I have twittered?
could you have twittered?
could he have twittered?
could we have twittered?
could you have twittered?
could they have twittered? 	could I have been twittering?
could you have been twittering?
could he have been twittering?
could we have been twittering?
could you have been twittering?
could they have been twittering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I twitter?
couldn't you twitter?
couldn't he twitter?
couldn't we twitter?
couldn't you twitter?
couldn't they twitter? 	couldn't I be twittering?
couldn't you be twittering?
couldn't he be twittering?
couldn't we be twittering?
couldn't you be twittering?
couldn't they be twittering? 	couldn't I have twittered?
couldn't you have twittered?
couldn't he have twittered?
couldn't we have twittered?
couldn't you have twittered?
couldn't they have twittered? 	couldn't I have been twittering?
couldn't you have been twittering?
couldn't he have been twittering?
couldn't we have been twittering?
couldn't you have been twittering?
couldn't they have been twittering?