| thoroughly | 7 | manner |
| regularly | 6 | degree |
| properly | 6 | manner |
| duct → be → cleaned | 116 |
| duct → need → cleaning | 13 |
| duct → require → cleaning | 3 |
| negative | neutral | positive |
| 0.358 | 0.494 | 0.149 |
| Raw frequency | 132 |
| Normalized frequency | 0.715 |
| Modifier score | 0.763 |
| Perplexity | 164.324 |