| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | not know the extent to | 5 |
|
| 2 | not know the extent to | 5 |
|
| 3 | [adv] know the extent to | 5 |
|
| 4 | [not/n't] know the extent to | 5 |
|
| 5 | know the extent to which | 10 |
|
| 6 | know the extent to [Wh det] | 10 |
|
| 7 | know the extent to [pron] | 10 |
|
| 8 | know the extent to which | 10 |
|
