| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] it necessary [to-vb] | 118 |
|
| 2 | it necessary [to-vb] [noun] | 45 |
|
| 3 | [vb past] it [to-vb] [noun] | 43 |
|
| 4 | [vb past] necessary [to-vb] [noun] | 6 |
|
