| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [vb infin] [been] [vb pp] [prep] | 509 |
|
| 2 | [vb infin] [been] [vb pp] [adv] [prep] | 385 |
|
| 3 | could [vb infin] [vb pp] [adv] [prep] | 195 |
|
| 4 | could [vb infin] [been] [vb pp] [adv] | 161 |
|
| 5 | could [vb infin] [been] [adv] [prep] | 20 |
|
