| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] could not be | 1289 |
|
| 2 | [Wh det] [modal v] not be | 943 |
|
| 3 | [Wh det] could [adv] be | 445 |
|
| 4 | [Wh det] could not [be] | 173 |
|
