| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could have [vb pp] [prep] [det] | 7 |
|
| 2 | they could have [vb pp] [prep] [det] | 7 |
|
| 3 | they could have [vb pp] [det] [noun] | 7 |
|
| 4 | they could have [vb pp] [det] [noun sg] | 5 |
|
