English verb conjugation
COULD OBSTRUCT

Regular verb: obstruct - obstructed - obstructed

Affirmation

Simple form	V-ing form
I could obstruct you could obstruct she could obstruct we could obstruct you could obstruct they could obstruct	I could be obstructing you could be obstructing she could be obstructing we could be obstructing you could be obstructing they could be obstructing
Perfect	V-ing perfect
I could have obstructed you could have obstructed she could have obstructed we could have obstructed you could have obstructed they could have obstructed	I could have been obstructing you could have been obstructing she could have been obstructing we could have been obstructing you could have been obstructing they could have been obstructing

Negation

Simple form	V-ing form
I couldn't obstruct you couldn't obstruct she couldn't obstruct we couldn't obstruct you couldn't obstruct they couldn't obstruct	I couldn't be obstructing you couldn't be obstructing she couldn't be obstructing we couldn't be obstructing you couldn't be obstructing they couldn't be obstructing
Perfect	V-ing perfect
I couldn't have obstructed you couldn't have obstructed she couldn't have obstructed we couldn't have obstructed you couldn't have obstructed they couldn't have obstructed	I couldn't have been obstructing you couldn't have been obstructing she couldn't have been obstructing we couldn't have been obstructing you couldn't have been obstructing they couldn't have been obstructing

Interrogative form

Simple form	V-ing form
could I obstruct? could you obstruct? could she obstruct? could we obstruct? could you obstruct? could they obstruct?	could I be obstructing? could you be obstructing? could she be obstructing? could we be obstructing? could you be obstructing? could they be obstructing?
Perfect	V-ing perfect
could I have obstructed? could you have obstructed? could she have obstructed? could we have obstructed? could you have obstructed? could they have obstructed?	could I have been obstructing? could you have been obstructing? could she have been obstructing? could we have been obstructing? could you have been obstructing? could they have been obstructing?

Interro-negative form

Simple form	V-ing form
couldn't I obstruct? couldn't you obstruct? couldn't she obstruct? couldn't we obstruct? couldn't you obstruct? couldn't they obstruct?	couldn't I be obstructing? couldn't you be obstructing? couldn't she be obstructing? couldn't we be obstructing? couldn't you be obstructing? couldn't they be obstructing?
Perfect	V-ing perfect
couldn't I have obstructed? couldn't you have obstructed? couldn't she have obstructed? couldn't we have obstructed? couldn't you have obstructed? couldn't they have obstructed?	couldn't I have been obstructing? couldn't you have been obstructing? couldn't she have been obstructing? couldn't we have been obstructing? couldn't you have been obstructing? couldn't they have been obstructing?