I'll be underestimating you'll be underestimating she'll be underestimating we'll be underestimating you'll be underestimating they'll be underestimating
Perfect
I'll have underestimated you'll have underestimated she'll have underestimated we'll have underestimated you'll have underestimated they'll have underestimated
V-ing perfect
I'll have been underestimating you'll have been underestimating she'll have been underestimating we'll have been underestimating you'll have been underestimating they'll have been underestimating
Negation
Simple form
I shan't underestimate you shan't underestimate she shan't underestimate we shan't underestimate you shan't underestimate they shan't underestimate
V-ing form
I shan't be underestimating you shan't be underestimating she shan't be underestimating we shan't be underestimating you shan't be underestimating they shan't be underestimating
Perfect
I shan't have underestimated you shan't have underestimated she shan't have underestimated we shan't have underestimated you shan't have underestimated they shan't have underestimated
V-ing perfect
I shan't have been underestimating you shan't have been underestimating she shan't have been underestimating we shan't have been underestimating you shan't have been underestimating they shan't have been underestimating
Interrogative form
Simple form
shall I underestimate? shall you underestimate? shall she underestimate? shall we underestimate? shall you underestimate? shall they underestimate?
V-ing form
shall I be underestimating? shall you be underestimating? shall she be underestimating? shall we be underestimating? shall you be underestimating? shall they be underestimating?
Perfect
shall I have underestimated? shall you have underestimated? shall she have underestimated? shall we have underestimated? shall you have underestimated? shall they have underestimated?
V-ing perfect
shall I have been underestimating? shall you have been underestimating? shall she have been underestimating? shall we have been underestimating? shall you have been underestimating? shall they have been underestimating?
Interro-negative form
Simple form
shan't I underestimate? shan't you underestimate? shan't she underestimate? shan't we underestimate? shan't you underestimate? shan't they underestimate?
V-ing form
shan't I be underestimating? shan't you be underestimating? shan't she be underestimating? shan't we be underestimating? shan't you be underestimating? shan't they be underestimating?
Perfect
shan't I have underestimated? shan't you have underestimated? shan't she have underestimated? shan't we have underestimated? shan't you have underestimated? shan't they have underestimated?
V-ing perfect
shan't I have been underestimating? shan't you have been underestimating? shan't she have been underestimating? shan't we have been underestimating? shan't you have been underestimating? shan't they have been underestimating?