| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] [modal v] [verb] [verb] | 1765 |
|
| 2 | [Wh det] [modal v] [verb] [vb pp] | 1230 |
|
| 3 | [pron] [modal v] [verb] occurred | 38 |
|
| 4 | [Wh det] [modal v] [verb] occur | 21 |
|
