| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh adv] did it start | 11 |
|
| 2 | [Wh adv] [vb past] it start | 11 |
|
| 3 | when [vb past] it start | 5 |
|
| 4 | how [vb past] it start | 5 |
|
