| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pers pn] could have been [verb] a | 11 |
|
| 2 | [pers pn] could have be [verb] a | 10 |
|
| 3 | [pers pn] could have be [verb] a | 9 |
|
| 4 | [pers pn] could have be [vb pp] a | 6 |
|
| 5 | [pers pn] could have be [v-ing] a | 5 |
|
| 6 | he could have be [verb] a | 5 |
|
