Present
I    obstruct
you  obstruct
he   obstructs
we   obstruct
you  obstruct
they obstruct

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

Past
I    obstructed
you  obstructed
he   obstructed
we   obstructed
you  obstructed
they obstructed

Pluperfect
I    had obstructed
you  had obstructed
he   had obstructed
we   had obstructed
you  had obstructed
they had obstructed

Future
I    will obstruct
you  will obstruct
he   will obstruct
we   will obstruct
you  will obstruct
they will obstruct

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

Present
I    obstruct
you  obstruct
he   obstruct
we   obstruct
you  obstruct
they obstruct

Present
I    have obstructed
you  have obstructed
he   have obstructed
we   have obstructed
you  have obstructed
they have obstructed

Imperfect
I    obstructed
you  obstructed
he   obstructed
we   obstructed
you  obstructed
they obstructed

Pluperfect
I    had obstructed
you  had obstructed
he   had obstructed
we   had obstructed
you  had obstructed
they had obstructed

Present
I    would obstruct
you  would obstruct
he   would obstruct
we   would obstruct
you  would obstruct
they would obstruct

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

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

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

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

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

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

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

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

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