could thwart
Regular verb: thwart - thwarted- thwarted

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could thwart
you could thwart
she could thwart
we could thwart
you could thwart
they could thwart 	I could be thwarting
you could be thwarting
she could be thwarting
we could be thwarting
you could be thwarting
they could be thwarting	I could have thwarted
you could have thwarted
she 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
she 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 couldn't thwart
you couldn't thwart
she couldn't thwart
we couldn't thwart
you couldn't thwart
they couldn't thwart 	I couldn't be thwarting
you couldn't be thwarting
she couldn't be thwarting
we couldn't be thwarting
you couldn't be thwarting
they couldn't be thwarting	I couldn't have thwarted
you couldn't have thwarted
she couldn't have thwarted
we couldn't have thwarted
you couldn't have thwarted
they couldn't have thwarted	I couldn't have been thwarting
you couldn't have been thwarting
she couldn't have been thwarting
we couldn't have been thwarting
you couldn't have been thwarting
they couldn't have been thwarting	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I thwart?
could you thwart?
could she thwart?
could we thwart?
could you thwart?
could they thwart? 	could I be thwarting?
could you be thwarting?
could she be thwarting?
could we be thwarting?
could you be thwarting?
could they be thwarting? 	could I have thwarted?
could you have thwarted?
could she 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 she 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 	
couldn't I thwart?
couldn't you thwart?
couldn't she thwart?
couldn't we thwart?
couldn't you thwart?
couldn't they thwart? 	couldn't I be thwarting?
couldn't you be thwarting?
couldn't she be thwarting?
couldn't we be thwarting?
couldn't you be thwarting?
couldn't they be thwarting? 	couldn't I have thwarted?
couldn't you have thwarted?
couldn't she have thwarted?
couldn't we have thwarted?
couldn't you have thwarted?
couldn't they have thwarted? 	couldn't I have been thwarting?
couldn't you have been thwarting?
couldn't she have been thwarting?
couldn't we have been thwarting?
couldn't you have been thwarting?
couldn't they have been thwarting?