| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb past] [verb] a | 638 |
|
| 2 | [pron] [vb past] [v-ing] a | 254 |
|
| 3 | it [verb] [v-ing] a | 63 |
|
| 4 | it [vb past] [v-ing] [art] | 59 |
|
