English verb conjugation
COULD UNDERSTATE

Regular verb: understate - understated - understated

Affirmation

Simple form	V-ing form
I could understate you could understate he could understate we could understate you could understate they could understate	I could be understating you could be understating he could be understating we could be understating you could be understating they could be understating
Perfect	V-ing perfect
I could have understated you could have understated he could have understated we could have understated you could have understated they could have understated	I could have been understating you could have been understating he could have been understating we could have been understating you could have been understating they could have been understating

Negation

Simple form	V-ing form
I couldn't understate you couldn't understate he couldn't understate we couldn't understate you couldn't understate they couldn't understate	I couldn't be understating you couldn't be understating he couldn't be understating we couldn't be understating you couldn't be understating they couldn't be understating
Perfect	V-ing perfect
I couldn't have understated you couldn't have understated he couldn't have understated we couldn't have understated you couldn't have understated they couldn't have understated	I couldn't have been understating you couldn't have been understating he couldn't have been understating we couldn't have been understating you couldn't have been understating they couldn't have been understating

Interrogative form

Simple form	V-ing form
could I understate? could you understate? could he understate? could we understate? could you understate? could they understate?	could I be understating? could you be understating? could he be understating? could we be understating? could you be understating? could they be understating?
Perfect	V-ing perfect
could I have understated? could you have understated? could he have understated? could we have understated? could you have understated? could they have understated?	could I have been understating? could you have been understating? could he have been understating? could we have been understating? could you have been understating? could they have been understating?

Interro-negative form

Simple form	V-ing form
couldn't I understate? couldn't you understate? couldn't he understate? couldn't we understate? couldn't you understate? couldn't they understate?	couldn't I be understating? couldn't you be understating? couldn't he be understating? couldn't we be understating? couldn't you be understating? couldn't they be understating?
Perfect	V-ing perfect
couldn't I have understated? couldn't you have understated? couldn't he have understated? couldn't we have understated? couldn't you have understated? couldn't they have understated?	couldn't I have been understating? couldn't you have been understating? couldn't he have been understating? couldn't we have been understating? couldn't you have been understating? couldn't they have been understating?