I can highlight you can highlight he can highlight we can highlight you can highlight they can highlight
V-ing form
I can be highlighting you can be highlighting he can be highlighting we can be highlighting you can be highlighting they can be highlighting
Perfect
I can have highlighted you can have highlighted he can have highlighted we can have highlighted you can have highlighted they can have highlighted
V-ing perfect
I can have been highlighting you can have been highlighting he can have been highlighting we can have been highlighting you can have been highlighting they can have been highlighting
Negation
Simple form
I can't highlight you can't highlight he can't highlight we can't highlight you can't highlight they can't highlight
V-ing form
I can't be highlighting you can't be highlighting he can't be highlighting we can't be highlighting you can't be highlighting they can't be highlighting
Perfect
I can't have highlighted you can't have highlighted he can't have highlighted we can't have highlighted you can't have highlighted they can't have highlighted
V-ing perfect
I can't have been highlighting you can't have been highlighting he can't have been highlighting we can't have been highlighting you can't have been highlighting they can't have been highlighting
Interrogative form
Simple form
can I highlight? can you highlight? can he highlight? can we highlight? can you highlight? can they highlight?
V-ing form
can I be highlighting? can you be highlighting? can he be highlighting? can we be highlighting? can you be highlighting? can they be highlighting?
Perfect
can I have highlighted? can you have highlighted? can he have highlighted? can we have highlighted? can you have highlighted? can they have highlighted?
V-ing perfect
can I have been highlighting? can you have been highlighting? can he have been highlighting? can we have been highlighting? can you have been highlighting? can they have been highlighting?
Interro-negative form
Simple form
can't I highlight? can't you highlight? can't he highlight? can't we highlight? can't you highlight? can't they highlight?
V-ing form
can't I be highlighting? can't you be highlighting? can't he be highlighting? can't we be highlighting? can't you be highlighting? can't they be highlighting?
Perfect
can't I have highlighted? can't you have highlighted? can't he have highlighted? can't we have highlighted? can't you have highlighted? can't they have highlighted?
V-ing perfect
can't I have been highlighting? can't you have been highlighting? can't he have been highlighting? can't we have been highlighting? can't you have been highlighting? can't they have been highlighting?