I have yet to see a single person wearing a mask on the street.

Each of them now seems to be wearing a mask.

In the morning they wear a mask of a particular design.

If you must work early in the day, wear a mask.

Like everyone else he'd seen so far, they were wearing masks.

If you come on anyone wearing a mask in this section, pay no attention.

But he's never gone to the trouble of wearing a mask.

But if he were wearing a mask, she could not see through it.

He looked like a different person, wearing a mask that used to be him.

Is that why you have to wear a mask over your head?