I can backcross you can backcross she can backcross we can backcross you can backcross they can backcross
V-ing form
I can be backcrossing you can be backcrossing she can be backcrossing we can be backcrossing you can be backcrossing they can be backcrossing
Perfect
I can have backcrossed you can have backcrossed she can have backcrossed we can have backcrossed you can have backcrossed they can have backcrossed
V-ing perfect
I can have been backcrossing you can have been backcrossing she can have been backcrossing we can have been backcrossing you can have been backcrossing they can have been backcrossing
Negation
Simple form
I cannot backcross you cannot backcross she cannot backcross we cannot backcross you cannot backcross they cannot backcross
V-ing form
I cannot be backcrossing you cannot be backcrossing she cannot be backcrossing we cannot be backcrossing you cannot be backcrossing they cannot be backcrossing
Perfect
I cannot have backcrossed you cannot have backcrossed she cannot have backcrossed we cannot have backcrossed you cannot have backcrossed they cannot have backcrossed
V-ing perfect
I cannot have been backcrossing you cannot have been backcrossing she cannot have been backcrossing we cannot have been backcrossing you cannot have been backcrossing they cannot have been backcrossing
Interrogative form
Simple form
can I backcross? can you backcross? can she backcross? can we backcross? can you backcross? can they backcross?
V-ing form
can I be backcrossing? can you be backcrossing? can she be backcrossing? can we be backcrossing? can you be backcrossing? can they be backcrossing?
Perfect
can I have backcrossed? can you have backcrossed? can she have backcrossed? can we have backcrossed? can you have backcrossed? can they have backcrossed?
V-ing perfect
can I have been backcrossing? can you have been backcrossing? can she have been backcrossing? can we have been backcrossing? can you have been backcrossing? can they have been backcrossing?
Interro-negative form
Simple form
can I not backcross? can you not backcross? can she not backcross? can we not backcross? can you not backcross? can they not backcross?
V-ing form
can I not be backcrossing? can you not be backcrossing? can she not be backcrossing? can we not be backcrossing? can you not be backcrossing? can they not be backcrossing?
Perfect
can I not have backcrossed? can you not have backcrossed? can she not have backcrossed? can we not have backcrossed? can you not have backcrossed? can they not have backcrossed?
V-ing perfect
can I not have been backcrossing? can you not have been backcrossing? can she not have been backcrossing? can we not have been backcrossing? can you not have been backcrossing? can they not have been backcrossing?