I can invigilate you can invigilate he can invigilate we can invigilate you can invigilate they can invigilate
V-ing form
I can be invigilating you can be invigilating he can be invigilating we can be invigilating you can be invigilating they can be invigilating
Perfect
I can have invigilated you can have invigilated he can have invigilated we can have invigilated you can have invigilated they can have invigilated
V-ing perfect
I can have been invigilating you can have been invigilating he can have been invigilating we can have been invigilating you can have been invigilating they can have been invigilating
Negation
Simple form
I can't invigilate you can't invigilate he can't invigilate we can't invigilate you can't invigilate they can't invigilate
V-ing form
I can't be invigilating you can't be invigilating he can't be invigilating we can't be invigilating you can't be invigilating they can't be invigilating
Perfect
I can't have invigilated you can't have invigilated he can't have invigilated we can't have invigilated you can't have invigilated they can't have invigilated
V-ing perfect
I can't have been invigilating you can't have been invigilating he can't have been invigilating we can't have been invigilating you can't have been invigilating they can't have been invigilating
Interrogative form
Simple form
can I invigilate? can you invigilate? can he invigilate? can we invigilate? can you invigilate? can they invigilate?
V-ing form
can I be invigilating? can you be invigilating? can he be invigilating? can we be invigilating? can you be invigilating? can they be invigilating?
Perfect
can I have invigilated? can you have invigilated? can he have invigilated? can we have invigilated? can you have invigilated? can they have invigilated?
V-ing perfect
can I have been invigilating? can you have been invigilating? can he have been invigilating? can we have been invigilating? can you have been invigilating? can they have been invigilating?
Interro-negative form
Simple form
can't I invigilate? can't you invigilate? can't he invigilate? can't we invigilate? can't you invigilate? can't they invigilate?
V-ing form
can't I be invigilating? can't you be invigilating? can't he be invigilating? can't we be invigilating? can't you be invigilating? can't they be invigilating?
Perfect
can't I have invigilated? can't you have invigilated? can't he have invigilated? can't we have invigilated? can't you have invigilated? can't they have invigilated?
V-ing perfect
can't I have been invigilating? can't you have been invigilating? can't he have been invigilating? can't we have been invigilating? can't you have been invigilating? can't they have been invigilating?