English verb conjugation
COULD BACKCROSS

Regular verb: backcross - backcrossed - backcrossed

Affirmation

Simple form	V-ing form
I could backcross you could backcross he could backcross we could backcross you could backcross they could backcross	I could be backcrossing you could be backcrossing he could be backcrossing we could be backcrossing you could be backcrossing they could be backcrossing
Perfect	V-ing perfect
I could have backcrossed you could have backcrossed he 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 he could have been backcrossing we could have been backcrossing you could have been backcrossing they could have been backcrossing

Negation

Simple form	V-ing form
I couldn't backcross you couldn't backcross he 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 he couldn't be backcrossing we couldn't be backcrossing you couldn't be backcrossing they couldn't be backcrossing
Perfect	V-ing perfect
I couldn't have backcrossed you couldn't have backcrossed he 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 he couldn't have been backcrossing we couldn't have been backcrossing you couldn't have been backcrossing they couldn't have been backcrossing

Interrogative form

Simple form	V-ing form
could I backcross? could you backcross? could he backcross? could we backcross? could you backcross? could they backcross?	could I be backcrossing? could you be backcrossing? could he be backcrossing? could we be backcrossing? could you be backcrossing? could they be backcrossing?
Perfect	V-ing perfect
could I have backcrossed? could you have backcrossed? could he 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 he have been backcrossing? could we have been backcrossing? could you have been backcrossing? could they have been backcrossing?

Interro-negative form

Simple form	V-ing form
couldn't I backcross? couldn't you backcross? couldn't he 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 he be backcrossing? couldn't we be backcrossing? couldn't you be backcrossing? couldn't they be backcrossing?
Perfect	V-ing perfect
couldn't I have backcrossed? couldn't you have backcrossed? couldn't he 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 he have been backcrossing? couldn't we have been backcrossing? couldn't you have been backcrossing? couldn't they have been backcrossing?