| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | when it [is] [adj] [to-vb] | 52 |
|
| 2 | when it is [adj] [verb] | 42 |
|
| 3 | when it [is] necessary [verb] | 17 |
|
| 4 | when it 's [adj] [verb] | 15 |
|
