| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have happened at [adj] [noun sg] | 5 |
|
| 2 | could have happened at [adj] [noun sg] | 5 |
|
| 3 | could have happened at [adj] [noun sg] | 5 |
|
| 4 | [modal v] have happened at [adj] [noun sg] | 5 |
|
| 5 | have happened at [art] [adj] [noun sg] | 11 |
|
| 6 | have happened at [art] [adj] [noun sg] | 11 |
|
| 7 | have happened at the [adj] [noun sg] | 7 |
|
| 8 | have happened at the [adj] [noun sg] | 7 |
|
