English verb conjugation
COULD SUBMARINE

Regular verb: submarine - submarined - submarined

Affirmation

Simple form	V-ing form
I could submarine you could submarine he could submarine we could submarine you could submarine they could submarine	I could be submarining you could be submarining he could be submarining we could be submarining you could be submarining they could be submarining
Perfect	V-ing perfect
I could have submarined you could have submarined he could have submarined we could have submarined you could have submarined they could have submarined	I could have been submarining you could have been submarining he could have been submarining we could have been submarining you could have been submarining they could have been submarining

Negation

Simple form	V-ing form
I couldn't submarine you couldn't submarine he couldn't submarine we couldn't submarine you couldn't submarine they couldn't submarine	I couldn't be submarining you couldn't be submarining he couldn't be submarining we couldn't be submarining you couldn't be submarining they couldn't be submarining
Perfect	V-ing perfect
I couldn't have submarined you couldn't have submarined he couldn't have submarined we couldn't have submarined you couldn't have submarined they couldn't have submarined	I couldn't have been submarining you couldn't have been submarining he couldn't have been submarining we couldn't have been submarining you couldn't have been submarining they couldn't have been submarining

Interrogative form

Simple form	V-ing form
could I submarine? could you submarine? could he submarine? could we submarine? could you submarine? could they submarine?	could I be submarining? could you be submarining? could he be submarining? could we be submarining? could you be submarining? could they be submarining?
Perfect	V-ing perfect
could I have submarined? could you have submarined? could he have submarined? could we have submarined? could you have submarined? could they have submarined?	could I have been submarining? could you have been submarining? could he have been submarining? could we have been submarining? could you have been submarining? could they have been submarining?

Interro-negative form

Simple form	V-ing form
couldn't I submarine? couldn't you submarine? couldn't he submarine? couldn't we submarine? couldn't you submarine? couldn't they submarine?	couldn't I be submarining? couldn't you be submarining? couldn't he be submarining? couldn't we be submarining? couldn't you be submarining? couldn't they be submarining?
Perfect	V-ing perfect
couldn't I have submarined? couldn't you have submarined? couldn't he have submarined? couldn't we have submarined? couldn't you have submarined? couldn't they have submarined?	couldn't I have been submarining? couldn't you have been submarining? couldn't he have been submarining? couldn't we have been submarining? couldn't you have been submarining? couldn't they have been submarining?