could tamper
Regular verb: tamper - tampered- tampered

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could tamper
you could tamper
he could tamper
we could tamper
you could tamper
they could tamper 	I could be tampering
you could be tampering
he could be tampering
we could be tampering
you could be tampering
they could be tampering	I could have tampered
you could have tampered
he could have tampered
we could have tampered
you could have tampered
they could have tampered	I could have been tampering
you could have been tampering
he could have been tampering
we could have been tampering
you could have been tampering
they could have been tampering	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not tamper
you could not tamper
he could not tamper
we could not tamper
you could not tamper
they could not tamper 	I could not be tampering
you could not be tampering
he could not be tampering
we could not be tampering
you could not be tampering
they could not be tampering	I could not have tampered
you could not have tampered
he could not have tampered
we could not have tampered
you could not have tampered
they could not have tampered	I could not have been tampering
you could not have been tampering
he could not have been tampering
we could not have been tampering
you could not have been tampering
they could not have been tampering	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I tamper?
could you tamper?
could he tamper?
could we tamper?
could you tamper?
could they tamper? 	could I be tampering?
could you be tampering?
could he be tampering?
could we be tampering?
could you be tampering?
could they be tampering? 	could I have tampered?
could you have tampered?
could he have tampered?
could we have tampered?
could you have tampered?
could they have tampered? 	could I have been tampering?
could you have been tampering?
could he have been tampering?
could we have been tampering?
could you have been tampering?
could they have been tampering? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not tamper?
could you not tamper?
could he not tamper?
could we not tamper?
could you not tamper?
could they not tamper? 	could I not be tampering?
could you not be tampering?
could he not be tampering?
could we not be tampering?
could you not be tampering?
could they not be tampering? 	could I not have tampered?
could you not have tampered?
could he not have tampered?
could we not have tampered?
could you not have tampered?
could they not have tampered? 	could I not have been tampering?
could you not have been tampering?
could he not have been tampering?
could we not have been tampering?
could you not have been tampering?
could they not have been tampering?