| Clue | Source | Date |
|---|---|---|
| Isn't kidding | Newsday | 23 Jul 2025 |
| Is serious | New York Times | 30 May 2025 |
| Is serious | New York Times | 04 Jun 2021 |
| Is not to be taken lightly | LA Times Daily | 03 Mar 2018 |
| Is not to be taken lightly | The Washington Post | 03 Mar 2018 |
| Is dead serious | New York Times | 04 Jan 2018 |
| Is dead serious | ||
| Is serious | LA Times Daily | 23 Feb 2017 |
| Isn't fooling | New York Times | 26 Mar 2016 |
| Is dead serious | ||
| Isn't kidding | ||
| Isn't joking | ||
| Isn't kidding | ||
| Isn't kidding | ||
| Is serious |