could thwart
Regular verb: thwart - thwarted- thwarted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could thwart
you could thwart
he could thwart
we could thwart
you could thwart
they could thwart 	I could be thwarting
you could be thwarting
he could be thwarting
we could be thwarting
you could be thwarting
they could be thwarting	I could have thwarted
you could have thwarted
he could have thwarted
we could have thwarted
you could have thwarted
they could have thwarted	I could have been thwarting
you could have been thwarting
he could have been thwarting
we could have been thwarting
you could have been thwarting
they could have been thwarting	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not thwart
you could not thwart
he could not thwart
we could not thwart
you could not thwart
they could not thwart 	I could not be thwarting
you could not be thwarting
he could not be thwarting
we could not be thwarting
you could not be thwarting
they could not be thwarting	I could not have thwarted
you could not have thwarted
he could not have thwarted
we could not have thwarted
you could not have thwarted
they could not have thwarted	I could not have been thwarting
you could not have been thwarting
he could not have been thwarting
we could not have been thwarting
you could not have been thwarting
they could not have been thwarting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I thwart?
could you thwart?
could he thwart?
could we thwart?
could you thwart?
could they thwart? 	could I be thwarting?
could you be thwarting?
could he be thwarting?
could we be thwarting?
could you be thwarting?
could they be thwarting? 	could I have thwarted?
could you have thwarted?
could he have thwarted?
could we have thwarted?
could you have thwarted?
could they have thwarted? 	could I have been thwarting?
could you have been thwarting?
could he have been thwarting?
could we have been thwarting?
could you have been thwarting?
could they have been thwarting? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not thwart?
could you not thwart?
could he not thwart?
could we not thwart?
could you not thwart?
could they not thwart? 	could I not be thwarting?
could you not be thwarting?
could he not be thwarting?
could we not be thwarting?
could you not be thwarting?
could they not be thwarting? 	could I not have thwarted?
could you not have thwarted?
could he not have thwarted?
could we not have thwarted?
could you not have thwarted?
could they not have thwarted? 	could I not have been thwarting?
could you not have been thwarting?
could he not have been thwarting?
could we not have been thwarting?
could you not have been thwarting?
could they not have been thwarting?