English verb conjugation
COULD INVIGILATE

Regular verb: invigilate - invigilated - invigilated

Affirmation

Simple form	V-ing form
I could invigilate you could invigilate he could invigilate we could invigilate you could invigilate they could invigilate	I could be invigilating you could be invigilating he could be invigilating we could be invigilating you could be invigilating they could be invigilating
Perfect	V-ing perfect
I could have invigilated you could have invigilated he could have invigilated we could have invigilated you could have invigilated they could have invigilated	I could have been invigilating you could have been invigilating he could have been invigilating we could have been invigilating you could have been invigilating they could have been invigilating

Negation

Simple form	V-ing form
I couldn't invigilate you couldn't invigilate he couldn't invigilate we couldn't invigilate you couldn't invigilate they couldn't invigilate	I couldn't be invigilating you couldn't be invigilating he couldn't be invigilating we couldn't be invigilating you couldn't be invigilating they couldn't be invigilating
Perfect	V-ing perfect
I couldn't have invigilated you couldn't have invigilated he couldn't have invigilated we couldn't have invigilated you couldn't have invigilated they couldn't have invigilated	I couldn't have been invigilating you couldn't have been invigilating he couldn't have been invigilating we couldn't have been invigilating you couldn't have been invigilating they couldn't have been invigilating

Interrogative form

Simple form	V-ing form
could I invigilate? could you invigilate? could he invigilate? could we invigilate? could you invigilate? could they invigilate?	could I be invigilating? could you be invigilating? could he be invigilating? could we be invigilating? could you be invigilating? could they be invigilating?
Perfect	V-ing perfect
could I have invigilated? could you have invigilated? could he have invigilated? could we have invigilated? could you have invigilated? could they have invigilated?	could I have been invigilating? could you have been invigilating? could he have been invigilating? could we have been invigilating? could you have been invigilating? could they have been invigilating?

Interro-negative form

Simple form	V-ing form
couldn't I invigilate? couldn't you invigilate? couldn't he invigilate? couldn't we invigilate? couldn't you invigilate? couldn't they invigilate?	couldn't I be invigilating? couldn't you be invigilating? couldn't he be invigilating? couldn't we be invigilating? couldn't you be invigilating? couldn't they be invigilating?
Perfect	V-ing perfect
couldn't I have invigilated? couldn't you have invigilated? couldn't he have invigilated? couldn't we have invigilated? couldn't you have invigilated? couldn't they have invigilated?	couldn't I have been invigilating? couldn't you have been invigilating? couldn't he have been invigilating? couldn't we have been invigilating? couldn't you have been invigilating? couldn't they have been invigilating?