could impinge
Regular verb: impinge - impinged- impinged

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could impinge
you could impinge
she could impinge
we could impinge
you could impinge
they could impinge 	I could be impinging
you could be impinging
she could be impinging
we could be impinging
you could be impinging
they could be impinging	I could have impinged
you could have impinged
she could have impinged
we could have impinged
you could have impinged
they could have impinged	I could have been impinging
you could have been impinging
she could have been impinging
we could have been impinging
you could have been impinging
they could have been impinging	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't impinge
you couldn't impinge
she couldn't impinge
we couldn't impinge
you couldn't impinge
they couldn't impinge 	I couldn't be impinging
you couldn't be impinging
she couldn't be impinging
we couldn't be impinging
you couldn't be impinging
they couldn't be impinging	I couldn't have impinged
you couldn't have impinged
she couldn't have impinged
we couldn't have impinged
you couldn't have impinged
they couldn't have impinged	I couldn't have been impinging
you couldn't have been impinging
she couldn't have been impinging
we couldn't have been impinging
you couldn't have been impinging
they couldn't have been impinging	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I impinge?
could you impinge?
could she impinge?
could we impinge?
could you impinge?
could they impinge? 	could I be impinging?
could you be impinging?
could she be impinging?
could we be impinging?
could you be impinging?
could they be impinging? 	could I have impinged?
could you have impinged?
could she have impinged?
could we have impinged?
could you have impinged?
could they have impinged? 	could I have been impinging?
could you have been impinging?
could she have been impinging?
could we have been impinging?
could you have been impinging?
could they have been impinging? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I impinge?
couldn't you impinge?
couldn't she impinge?
couldn't we impinge?
couldn't you impinge?
couldn't they impinge? 	couldn't I be impinging?
couldn't you be impinging?
couldn't she be impinging?
couldn't we be impinging?
couldn't you be impinging?
couldn't they be impinging? 	couldn't I have impinged?
couldn't you have impinged?
couldn't she have impinged?
couldn't we have impinged?
couldn't you have impinged?
couldn't they have impinged? 	couldn't I have been impinging?
couldn't you have been impinging?
couldn't she have been impinging?
couldn't we have been impinging?
couldn't you have been impinging?
couldn't they have been impinging?