| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | when it [verb] a | 37 |
|
| 2 | when it [vb past] a | 31 |
|
| 3 | when it become a | 8 |
|
| 4 | when it became a | 7 |
|
| 5 | when it [vb -s] a | 6 |
|
