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 can't cross you can't cross she can't cross we can't cross you can't cross they can't cross
V-ing form
I can't be crossing you can't be crossing she can't be crossing we can't be crossing you can't be crossing they can't be crossing
Perfect
I can't have crossed you can't have crossed she can't have crossed we can't have crossed you can't have crossed they can't have crossed
V-ing perfect
I can't have been crossing you can't have been crossing she can't have been crossing we can't have been crossing you can't have been crossing they can't 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't I cross? can't you cross? can't she cross? can't we cross? can't you cross? can't they cross?
V-ing form
can't I be crossing? can't you be crossing? can't she be crossing? can't we be crossing? can't you be crossing? can't they be crossing?
Perfect
can't I have crossed? can't you have crossed? can't she have crossed? can't we have crossed? can't you have crossed? can't they have crossed?
V-ing perfect
can't I have been crossing? can't you have been crossing? can't she have been crossing? can't we have been crossing? can't you have been crossing? can't they have been crossing?