| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] could not | 17937 |
|
| 2 | [Wh pn] [vb mod] not | 1799 |
|
| 3 | [Wh pn] [modal v] not | 1799 |
|
| 4 | [Wh pn] could [adv] | 681 |
|
| 5 | [Wh pn] could not | 445 |
|
