| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they could [not/n't] [vb infin] a [adj] | 16 |
|
| 2 | they could [not/n't] [verb] a [adj] | 14 |
|
| 3 | they could n't [verb] a [adj] | 9 |
|
| 4 | they could not [verb] a [adj] | 7 |
|
