| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | why could [pers pn] [adv] [verb] | 14 |
|
| 2 | why could [pron] [adv] [verb] | 14 |
|
| 3 | why could [pron] [adv] [vb infin] | 14 |
|
| 4 | why could [pron] [not/n't] [verb] | 9 |
|
| 5 | why could [pron] not [verb] | 9 |
|
| 6 | why could [pron] not [verb] | 9 |
|
| 7 | why could [pron] [adv] [verb] | 5 |
|
| 8 | why could [pron] never [verb] | 5 |
|
| 9 | why could [pron] never [verb] | 5 |
|
