| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it [is] [adv] necessary [verb] | 31 |
|
| 2 | [subord] it is [adv] necessary [verb] | 30 |
|
| 3 | [subord] it [is] [adv] necessary [to-vb] | 30 |
|
| 4 | [subord] it [is] [adv] necessary [verb] | 19 |
|
| 5 | [subord] it [is] [not/n't] necessary [verb] | 12 |
|
| 6 | [subord] it [is] not necessary [verb] | 12 |
|
| 7 | [subord] it [is] not necessary [verb] | 12 |
|
| 8 | although it [is] [adv] necessary [verb] | 6 |
|
