| over time | 7 | temporal |
| across the surface | 3 | location |
| due to smoking | 3 | cause |
| tooth → look → grey | 20 |
| tooth → turn → grey | 17 |
| tooth → become → grey | 15 |
| tooth → appear → grey | 9 |
| tooth → get → grey | 4 |
| tooth → go → grey | 3 |
| negative | neutral | positive |
| 0.615 | 0.342 | 0.043 |
| Raw frequency | 68 |
| Normalized frequency | 0.404 |
| Modifier score | 0.500 |
| Perplexity | 305.745 |