| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [adv] have [vb pp] a | 5 |
|
| 2 | they could have [vb pp] [prep] a | 5 |
|
| 3 | they could have [vb pp] [prep] a | 5 |
|
| 4 | they could have [vb pp] a [adj] | 7 |
|
| 5 | they could have [vb pp] a [noun] | 7 |
|
| 6 | they could have [vb pp] a [noun sg] | 7 |
|
| 7 | they could have [vb pp] a [adj] | 5 |
|
