Present
I    underestimate
you  underestimate
he   underestimates
we   underestimate
you  underestimate
they underestimate

Perfect
I    have underestimated
you  have underestimated
he   has underestimated
we   have underestimated
you  have underestimated
they have underestimated

Past
I    underestimated
you  underestimated
he   underestimated
we   underestimated
you  underestimated
they underestimated

Pluperfect
I    had underestimated
you  had underestimated
he   had underestimated
we   had underestimated
you  had underestimated
they had underestimated

Future
I    will underestimate
you  will underestimate
he   will underestimate
we   will underestimate
you  will underestimate
they will underestimate

Future perfect
I    will have underestimated
you  will have underestimated
he   will have underestimated
we   will have underestimated
you  will have underestimated
they will have underestimated

Present
I    underestimate
you  underestimate
he   underestimate
we   underestimate
you  underestimate
they underestimate

Present
I    have underestimated
you  have underestimated
he   have underestimated
we   have underestimated
you  have underestimated
they have underestimated

Imperfect
I    underestimated
you  underestimated
he   underestimated
we   underestimated
you  underestimated
they underestimated

Pluperfect
I    had underestimated
you  had underestimated
he   had underestimated
we   had underestimated
you  had underestimated
they had underestimated

Present
I    would underestimate
you  would underestimate
he   would underestimate
we   would underestimate
you  would underestimate
they would underestimate

Perfect
I    would have underestimated
you  would have underestimated
he   would have underestimated
we   would have underestimated
you  would have underestimated
they would have underestimated

Present
I    am underestimating
you  are underestimating
he   is underestimating
we   are underestimating
you  are underestimating
they are underestimating

Perfect
I    have been underestimating
you  have been underestimating
he   has been underestimating
we   have been underestimating
you  have been underestimating
they have been underestimating

Past
I    was underestimating
you  were underestimating
he   was underestimating
we   were underestimating
you  were underestimating
they were underestimating

Pluperfect
I    had been underestimating
you  had been underestimating
he   had been underestimating
we   had been underestimating
you  had been underestimating
they had been underestimating

Future
I    will be underestimating
you  will be underestimating
he   will be underestimating
we   will be underestimating
you  will be underestimating
they will be underestimating

Future perfect
I    will have been underestimating
you  will have been underestimating
he   will have been underestimating
we   will have been underestimating
you  will have been underestimating
they will have been underestimating

Present
I    would be underestimating
you  would be underestimating
he   would be underestimating
we   would be underestimating
you  would be underestimating
they would be underestimating

Perfect
I    would have been underestimating
you  would have been underestimating
he   would have been underestimating
we   would have been underestimating
you  would have been underestimating
they would have been underestimating