| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [verb] a | 273 |
|
| 2 | could have [vb pp] a | 273 |
|
| 3 | [modal v] have heard a | 15 |
|
| 4 | [vb mod] have heard a | 15 |
|
| 5 | could have heard [art] | 11 |
|
| 6 | could have heard [art] | 11 |
|
| 7 | could have heard a | 10 |
|
| 8 | could [vb infin] heard a | 10 |
|
| 9 | could [verb] heard a | 10 |
|
| 10 | could have hear a | 9 |
|
| 11 | could have heard a | 9 |
|
| 12 | could have heard a | 9 |
|
