| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] have been [prep] | 15 |
|
| 2 | could [adv] [vb infin] been [prep] | 15 |
|
| 3 | could [adv] have been [prep] | 15 |
|
| 4 | could [adv] [verb] been [prep] | 15 |
|
| 5 | could [adv] [verb] been in | 8 |
|
