English verb conjugation
COULD OVERESTIMATE

Regular verb: overestimate - overestimated - overestimated

Affirmation

Simple form	V-ing form
I could overestimate you could overestimate he could overestimate we could overestimate you could overestimate they could overestimate	I could be overestimating you could be overestimating he could be overestimating we could be overestimating you could be overestimating they could be overestimating
Perfect	V-ing perfect
I could have overestimated you could have overestimated he could have overestimated we could have overestimated you could have overestimated they could have overestimated	I could have been overestimating you could have been overestimating he could have been overestimating we could have been overestimating you could have been overestimating they could have been overestimating

Negation

Simple form	V-ing form
I couldn't overestimate you couldn't overestimate he couldn't overestimate we couldn't overestimate you couldn't overestimate they couldn't overestimate	I couldn't be overestimating you couldn't be overestimating he couldn't be overestimating we couldn't be overestimating you couldn't be overestimating they couldn't be overestimating
Perfect	V-ing perfect
I couldn't have overestimated you couldn't have overestimated he couldn't have overestimated we couldn't have overestimated you couldn't have overestimated they couldn't have overestimated	I couldn't have been overestimating you couldn't have been overestimating he couldn't have been overestimating we couldn't have been overestimating you couldn't have been overestimating they couldn't have been overestimating

Interrogative form

Simple form	V-ing form
could I overestimate? could you overestimate? could he overestimate? could we overestimate? could you overestimate? could they overestimate?	could I be overestimating? could you be overestimating? could he be overestimating? could we be overestimating? could you be overestimating? could they be overestimating?
Perfect	V-ing perfect
could I have overestimated? could you have overestimated? could he have overestimated? could we have overestimated? could you have overestimated? could they have overestimated?	could I have been overestimating? could you have been overestimating? could he have been overestimating? could we have been overestimating? could you have been overestimating? could they have been overestimating?

Interro-negative form

Simple form	V-ing form
couldn't I overestimate? couldn't you overestimate? couldn't he overestimate? couldn't we overestimate? couldn't you overestimate? couldn't they overestimate?	couldn't I be overestimating? couldn't you be overestimating? couldn't he be overestimating? couldn't we be overestimating? couldn't you be overestimating? couldn't they be overestimating?
Perfect	V-ing perfect
couldn't I have overestimated? couldn't you have overestimated? couldn't he have overestimated? couldn't we have overestimated? couldn't you have overestimated? couldn't they have overestimated?	couldn't I have been overestimating? couldn't you have been overestimating? couldn't he have been overestimating? couldn't we have been overestimating? couldn't you have been overestimating? couldn't they have been overestimating?