| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [adv] [verb] [been] [adj] | 178 |
|
| 2 | [modal v] [adv] [verb] [been] [det] | 113 |
|
| 3 | could [adv] [verb] [be] [det] | 29 |
|
