The clerk did not know when he would return.

Ahmed spoke no English, but the clerk did not know that.

The clerks don't always know the price offhand, but they are happy to check.

When scholars call looking for books, the clerks who answer know what they are talking about.

Whoever passed by the window, the clerk on duty knew instantly whether he had paid or not.

The clerk doesn't know where they are, so I said we'd call back.

Upon arriving in two hours, each clerk will know precisely where to begin.

But that was because the clerk did not know who was coming for the necklace.

"When I went into stores, all the clerks knew my clothing size."

If the clerk did not know what he meant he would take his business elsewhere.