could twin
Regular verb: twin - twinned- twinned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could twin
you could twin
she could twin
we could twin
you could twin
they could twin 	I could be twinning
you could be twinning
she could be twinning
we could be twinning
you could be twinning
they could be twinning	I could have twinned
you could have twinned
she could have twinned
we could have twinned
you could have twinned
they could have twinned	I could have been twinning
you could have been twinning
she could have been twinning
we could have been twinning
you could have been twinning
they could have been twinning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't twin
you couldn't twin
she couldn't twin
we couldn't twin
you couldn't twin
they couldn't twin 	I couldn't be twinning
you couldn't be twinning
she couldn't be twinning
we couldn't be twinning
you couldn't be twinning
they couldn't be twinning	I couldn't have twinned
you couldn't have twinned
she couldn't have twinned
we couldn't have twinned
you couldn't have twinned
they couldn't have twinned	I couldn't have been twinning
you couldn't have been twinning
she couldn't have been twinning
we couldn't have been twinning
you couldn't have been twinning
they couldn't have been twinning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I twin?
could you twin?
could she twin?
could we twin?
could you twin?
could they twin? 	could I be twinning?
could you be twinning?
could she be twinning?
could we be twinning?
could you be twinning?
could they be twinning? 	could I have twinned?
could you have twinned?
could she have twinned?
could we have twinned?
could you have twinned?
could they have twinned? 	could I have been twinning?
could you have been twinning?
could she have been twinning?
could we have been twinning?
could you have been twinning?
could they have been twinning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I twin?
couldn't you twin?
couldn't she twin?
couldn't we twin?
couldn't you twin?
couldn't they twin? 	couldn't I be twinning?
couldn't you be twinning?
couldn't she be twinning?
couldn't we be twinning?
couldn't you be twinning?
couldn't they be twinning? 	couldn't I have twinned?
couldn't you have twinned?
couldn't she have twinned?
couldn't we have twinned?
couldn't you have twinned?
couldn't they have twinned? 	couldn't I have been twinning?
couldn't you have been twinning?
couldn't she have been twinning?
couldn't we have been twinning?
couldn't you have been twinning?
couldn't they have been twinning?