English verb conjugation
COULD TWIN

Regular verb: twin - twinned - twinned

Affirmation

Simple form	V-ing form
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
Perfect	V-ing perfect
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
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
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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
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?
Perfect	V-ing perfect
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?