| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] necessary [to-vb] | 1094 |
|
| 2 | it [is] not necessary | 306 |
|
| 3 | [is] not necessary [to-vb] | 199 |
|
| 4 | it [is] not [to-vb] | 59 |
|
