Present
I    cost
you  cost
he   costs
we   cost
you  cost
they cost

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

Past
I    cost
you  cost
he   cost
we   cost
you  cost
they cost

Pluperfect
I    had cost
you  had cost
he   had cost
we   had cost
you  had cost
they had cost

Future
I    will cost
you  will cost
he   will cost
we   will cost
you  will cost
they will cost

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

Present
I    cost
you  cost
he   cost
we   cost
you  cost
they cost

Present
I    have cost
you  have cost
he   have cost
we   have cost
you  have cost
they have cost

Imperfect
I    cost
you  cost
he   cost
we   cost
you  cost
they cost

Pluperfect
I    had cost
you  had cost
he   had cost
we   had cost
you  had cost
they had cost

Present
I    would cost
you  would cost
he   would cost
we   would cost
you  would cost
they would cost

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

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

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

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

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

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

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

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

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