| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which had [adv] | 1424 |
|
| 2 | [pron] had once | 591 |
|
| 3 | which [verb] once | 97 |
|
| 4 | which [vb past] once | 87 |
|
| 5 | which have once | 82 |
|
