English verb conjugation
COULD OVERTURN

Regular verb: overturn - overturned - overturned

Affirmation

Simple form	V-ing form
I could overturn you could overturn she could overturn we could overturn you could overturn they could overturn	I could be overturning you could be overturning she could be overturning we could be overturning you could be overturning they could be overturning
Perfect	V-ing perfect
I could have overturned you could have overturned she could have overturned we could have overturned you could have overturned they could have overturned	I could have been overturning you could have been overturning she could have been overturning we could have been overturning you could have been overturning they could have been overturning

Negation

Simple form	V-ing form
I couldn't overturn you couldn't overturn she couldn't overturn we couldn't overturn you couldn't overturn they couldn't overturn	I couldn't be overturning you couldn't be overturning she couldn't be overturning we couldn't be overturning you couldn't be overturning they couldn't be overturning
Perfect	V-ing perfect
I couldn't have overturned you couldn't have overturned she couldn't have overturned we couldn't have overturned you couldn't have overturned they couldn't have overturned	I couldn't have been overturning you couldn't have been overturning she couldn't have been overturning we couldn't have been overturning you couldn't have been overturning they couldn't have been overturning

Interrogative form

Simple form	V-ing form
could I overturn? could you overturn? could she overturn? could we overturn? could you overturn? could they overturn?	could I be overturning? could you be overturning? could she be overturning? could we be overturning? could you be overturning? could they be overturning?
Perfect	V-ing perfect
could I have overturned? could you have overturned? could she have overturned? could we have overturned? could you have overturned? could they have overturned?	could I have been overturning? could you have been overturning? could she have been overturning? could we have been overturning? could you have been overturning? could they have been overturning?

Interro-negative form

Simple form	V-ing form
couldn't I overturn? couldn't you overturn? couldn't she overturn? couldn't we overturn? couldn't you overturn? couldn't they overturn?	couldn't I be overturning? couldn't you be overturning? couldn't she be overturning? couldn't we be overturning? couldn't you be overturning? couldn't they be overturning?
Perfect	V-ing perfect
couldn't I have overturned? couldn't you have overturned? couldn't she have overturned? couldn't we have overturned? couldn't you have overturned? couldn't they have overturned?	couldn't I have been overturning? couldn't you have been overturning? couldn't she have been overturning? couldn't we have been overturning? couldn't you have been overturning? couldn't they have been overturning?