I can cross you can cross she can cross we can cross you can cross they can cross
V-ing form
I can be crossing you can be crossing she can be crossing we can be crossing you can be crossing they can be crossing
Perfect
I can have crossed you can have crossed she can have crossed we can have crossed you can have crossed they can have crossed
V-ing perfect
I can have been crossing you can have been crossing she can have been crossing we can have been crossing you can have been crossing they can have been crossing
Negation
Simple form
I cannot cross you cannot cross she cannot cross we cannot cross you cannot cross they cannot cross
V-ing form
I cannot be crossing you cannot be crossing she cannot be crossing we cannot be crossing you cannot be crossing they cannot be crossing
Perfect
I cannot have crossed you cannot have crossed she cannot have crossed we cannot have crossed you cannot have crossed they cannot have crossed
V-ing perfect
I cannot have been crossing you cannot have been crossing she cannot have been crossing we cannot have been crossing you cannot have been crossing they cannot have been crossing
Interrogative form
Simple form
can I cross? can you cross? can she cross? can we cross? can you cross? can they cross?
V-ing form
can I be crossing? can you be crossing? can she be crossing? can we be crossing? can you be crossing? can they be crossing?
Perfect
can I have crossed? can you have crossed? can she have crossed? can we have crossed? can you have crossed? can they have crossed?
V-ing perfect
can I have been crossing? can you have been crossing? can she have been crossing? can we have been crossing? can you have been crossing? can they have been crossing?
Interro-negative form
Simple form
can I not cross? can you not cross? can she not cross? can we not cross? can you not cross? can they not cross?
V-ing form
can I not be crossing? can you not be crossing? can she not be crossing? can we not be crossing? can you not be crossing? can they not be crossing?
Perfect
can I not have crossed? can you not have crossed? can she not have crossed? can we not have crossed? can you not have crossed? can they not have crossed?
V-ing perfect
can I not have been crossing? can you not have been crossing? can she not have been crossing? can we not have been crossing? can you not have been crossing? can they not have been crossing?