English verb conjugation
COULD SENTINEL

Regular verb: sentinel - sentineled - sentineled

Affirmation

Simple form	V-ing form
I could sentinel you could sentinel he could sentinel we could sentinel you could sentinel they could sentinel	I could be sentineling you could be sentineling he could be sentineling we could be sentineling you could be sentineling they could be sentineling
Perfect	V-ing perfect
I could have sentineled you could have sentineled he could have sentineled we could have sentineled you could have sentineled they could have sentineled	I could have been sentineling you could have been sentineling he could have been sentineling we could have been sentineling you could have been sentineling they could have been sentineling

Negation

Simple form	V-ing form
I couldn't sentinel you couldn't sentinel he couldn't sentinel we couldn't sentinel you couldn't sentinel they couldn't sentinel	I couldn't be sentineling you couldn't be sentineling he couldn't be sentineling we couldn't be sentineling you couldn't be sentineling they couldn't be sentineling
Perfect	V-ing perfect
I couldn't have sentineled you couldn't have sentineled he couldn't have sentineled we couldn't have sentineled you couldn't have sentineled they couldn't have sentineled	I couldn't have been sentineling you couldn't have been sentineling he couldn't have been sentineling we couldn't have been sentineling you couldn't have been sentineling they couldn't have been sentineling

Interrogative form

Simple form	V-ing form
could I sentinel? could you sentinel? could he sentinel? could we sentinel? could you sentinel? could they sentinel?	could I be sentineling? could you be sentineling? could he be sentineling? could we be sentineling? could you be sentineling? could they be sentineling?
Perfect	V-ing perfect
could I have sentineled? could you have sentineled? could he have sentineled? could we have sentineled? could you have sentineled? could they have sentineled?	could I have been sentineling? could you have been sentineling? could he have been sentineling? could we have been sentineling? could you have been sentineling? could they have been sentineling?

Interro-negative form

Simple form	V-ing form
couldn't I sentinel? couldn't you sentinel? couldn't he sentinel? couldn't we sentinel? couldn't you sentinel? couldn't they sentinel?	couldn't I be sentineling? couldn't you be sentineling? couldn't he be sentineling? couldn't we be sentineling? couldn't you be sentineling? couldn't they be sentineling?
Perfect	V-ing perfect
couldn't I have sentineled? couldn't you have sentineled? couldn't he have sentineled? couldn't we have sentineled? couldn't you have sentineled? couldn't they have sentineled?	couldn't I have been sentineling? couldn't you have been sentineling? couldn't he have been sentineling? couldn't we have been sentineling? couldn't you have been sentineling? couldn't they have been sentineling?