could invert
Regular verb: invert - inverted- inverted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could invert
you could invert
she could invert
we could invert
you could invert
they could invert 	I could be inverting
you could be inverting
she could be inverting
we could be inverting
you could be inverting
they could be inverting	I could have inverted
you could have inverted
she could have inverted
we could have inverted
you could have inverted
they could have inverted	I could have been inverting
you could have been inverting
she could have been inverting
we could have been inverting
you could have been inverting
they could have been inverting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not invert
you could not invert
she could not invert
we could not invert
you could not invert
they could not invert 	I could not be inverting
you could not be inverting
she could not be inverting
we could not be inverting
you could not be inverting
they could not be inverting	I could not have inverted
you could not have inverted
she could not have inverted
we could not have inverted
you could not have inverted
they could not have inverted	I could not have been inverting
you could not have been inverting
she could not have been inverting
we could not have been inverting
you could not have been inverting
they could not have been inverting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I invert?
could you invert?
could she invert?
could we invert?
could you invert?
could they invert? 	could I be inverting?
could you be inverting?
could she be inverting?
could we be inverting?
could you be inverting?
could they be inverting? 	could I have inverted?
could you have inverted?
could she have inverted?
could we have inverted?
could you have inverted?
could they have inverted? 	could I have been inverting?
could you have been inverting?
could she have been inverting?
could we have been inverting?
could you have been inverting?
could they have been inverting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not invert?
could you not invert?
could she not invert?
could we not invert?
could you not invert?
could they not invert? 	could I not be inverting?
could you not be inverting?
could she not be inverting?
could we not be inverting?
could you not be inverting?
could they not be inverting? 	could I not have inverted?
could you not have inverted?
could she not have inverted?
could we not have inverted?
could you not have inverted?
could they not have inverted? 	could I not have been inverting?
could you not have been inverting?
could she not have been inverting?
could we not have been inverting?
could you not have been inverting?
could they not have been inverting?