could backcross
Verbe régulier : backcross - backcrossed- backcrossed

Affirmation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I could backcross
you could backcross
she could backcross
we could backcross
you could backcross
they could backcross 	I could be backcrossing
you could be backcrossing
she could be backcrossing
we could be backcrossing
you could be backcrossing
they could be backcrossing	I could have backcrossed
you could have backcrossed
she could have backcrossed
we could have backcrossed
you could have backcrossed
they could have backcrossed	I could have been backcrossing
you could have been backcrossing
she could have been backcrossing
we could have been backcrossing
you could have been backcrossing
they could have been backcrossing	

Négation 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
I couldn't backcross
you couldn't backcross
she couldn't backcross
we couldn't backcross
you couldn't backcross
they couldn't backcross 	I couldn't be backcrossing
you couldn't be backcrossing
she couldn't be backcrossing
we couldn't be backcrossing
you couldn't be backcrossing
they couldn't be backcrossing	I couldn't have backcrossed
you couldn't have backcrossed
she couldn't have backcrossed
we couldn't have backcrossed
you couldn't have backcrossed
they couldn't have backcrossed	I couldn't have been backcrossing
you couldn't have been backcrossing
she couldn't have been backcrossing
we couldn't have been backcrossing
you couldn't have been backcrossing
they couldn't have been backcrossing	

Forme interrogative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
could I backcross?
could you backcross?
could she backcross?
could we backcross?
could you backcross?
could they backcross? 	could I be backcrossing?
could you be backcrossing?
could she be backcrossing?
could we be backcrossing?
could you be backcrossing?
could they be backcrossing? 	could I have backcrossed?
could you have backcrossed?
could she have backcrossed?
could we have backcrossed?
could you have backcrossed?
could they have backcrossed? 	could I have been backcrossing?
could you have been backcrossing?
could she have been backcrossing?
could we have been backcrossing?
could you have been backcrossing?
could they have been backcrossing? 	

Forme interro-négative 	
Forme simple 	Forme en V-ing 	Perfect 	Perfect en V-ing 	
couldn't I backcross?
couldn't you backcross?
couldn't she backcross?
couldn't we backcross?
couldn't you backcross?
couldn't they backcross? 	couldn't I be backcrossing?
couldn't you be backcrossing?
couldn't she be backcrossing?
couldn't we be backcrossing?
couldn't you be backcrossing?
couldn't they be backcrossing? 	couldn't I have backcrossed?
couldn't you have backcrossed?
couldn't she have backcrossed?
couldn't we have backcrossed?
couldn't you have backcrossed?
couldn't they have backcrossed? 	couldn't I have been backcrossing?
couldn't you have been backcrossing?
couldn't she have been backcrossing?
couldn't we have been backcrossing?
couldn't you have been backcrossing?
couldn't they have been backcrossing?