I might underestimate you might underestimate he might underestimate we might underestimate you might underestimate they might underestimate
V-ing form
I might be underestimating you might be underestimating he might be underestimating we might be underestimating you might be underestimating they might be underestimating
Perfect
I might have underestimated you might have underestimated he might have underestimated we might have underestimated you might have underestimated they might have underestimated
V-ing perfect
I might have been underestimating you might have been underestimating he might have been underestimating we might have been underestimating you might have been underestimating they might have been underestimating
Negation
Simple form
I mightn't underestimate you mightn't underestimate he mightn't underestimate we mightn't underestimate you mightn't underestimate they mightn't underestimate
V-ing form
I mightn't be underestimating you mightn't be underestimating he mightn't be underestimating we mightn't be underestimating you mightn't be underestimating they mightn't be underestimating
Perfect
I mightn't have underestimated you mightn't have underestimated he mightn't have underestimated we mightn't have underestimated you mightn't have underestimated they mightn't have underestimated
V-ing perfect
I mightn't have been underestimating you mightn't have been underestimating he mightn't have been underestimating we mightn't have been underestimating you mightn't have been underestimating they mightn't have been underestimating
Interrogative form
Simple form
might I underestimate? might you underestimate? might he underestimate? might we underestimate? might you underestimate? might they underestimate?
V-ing form
might I be underestimating? might you be underestimating? might he be underestimating? might we be underestimating? might you be underestimating? might they be underestimating?
Perfect
might I have underestimated? might you have underestimated? might he have underestimated? might we have underestimated? might you have underestimated? might they have underestimated?
V-ing perfect
might I have been underestimating? might you have been underestimating? might he have been underestimating? might we have been underestimating? might you have been underestimating? might they have been underestimating?
Interro-negative form
Simple form
mightn't I underestimate? mightn't you underestimate? mightn't he underestimate? mightn't we underestimate? mightn't you underestimate? mightn't they underestimate?
V-ing form
mightn't I be underestimating? mightn't you be underestimating? mightn't he be underestimating? mightn't we be underestimating? mightn't you be underestimating? mightn't they be underestimating?
Perfect
mightn't I have underestimated? mightn't you have underestimated? mightn't he have underestimated? mightn't we have underestimated? mightn't you have underestimated? mightn't they have underestimated?
V-ing perfect
mightn't I have been underestimating? mightn't you have been underestimating? mightn't he have been underestimating? mightn't we have been underestimating? mightn't you have been underestimating? mightn't they have been underestimating?