upon

Last Updated : Jul 20, 2023 |

You can usually replace upon with on. When you introduce a condition or event, use when instead of upon.

Preferred

Discouraged

Create a new policy list based on an existing list.

Create a new policy list based upon an existing list.

When answering the call, the attendant hears call identification tones.

Upon answering the call, the attendant hears call identification tones.