He carried a sac on his back.

He is a sack o' shit.

He got a sack-whack from his friend during the game.

The R. I. S.s are conducting an investigation.

He tried to tackle the opponent, but he went down like a sack of potatoes.

He has worn sackcloth and ashes as a sign of repentance.

He wears sackcloth and ashes.

They are wearing sackcloth and ashes as a sign of mourning.

They wear sackcloth and ashes as a sign of mourning.

They wore sackcloth and ashes as a sign of mourning.