English verb conjugation
COULD INVIGILATE

Regular verb: invigilate - invigilated - invigilated

Affirmation

Simple form	V-ing form
I could invigilate you could invigilate she could invigilate we could invigilate you could invigilate they could invigilate	I could be invigilating you could be invigilating she 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 she 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 she 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 could not invigilate you could not invigilate she could not invigilate we could not invigilate you could not invigilate they could not invigilate	I could not be invigilating you could not be invigilating she could not be invigilating we could not be invigilating you could not be invigilating they could not be invigilating
Perfect	V-ing perfect
I could not have invigilated you could not have invigilated she could not have invigilated we could not have invigilated you could not have invigilated they could not have invigilated	I could not have been invigilating you could not have been invigilating she could not have been invigilating we could not have been invigilating you could not have been invigilating they could not have been invigilating

Interrogative form

Simple form	V-ing form
could I invigilate? could you invigilate? could she invigilate? could we invigilate? could you invigilate? could they invigilate?	could I be invigilating? could you be invigilating? could she 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 she 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 she 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
could I not invigilate? could you not invigilate? could she not invigilate? could we not invigilate? could you not invigilate? could they not invigilate?	could I not be invigilating? could you not be invigilating? could she not be invigilating? could we not be invigilating? could you not be invigilating? could they not be invigilating?
Perfect	V-ing perfect
could I not have invigilated? could you not have invigilated? could she not have invigilated? could we not have invigilated? could you not have invigilated? could they not have invigilated?	could I not have been invigilating? could you not have been invigilating? could she not have been invigilating? could we not have been invigilating? could you not have been invigilating? could they not have been invigilating?