| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb past] be [adj] | 535 |
|
| 2 | it [vb past] be [adj] | 371 |
|
| 3 | it [verb] be necessary | 48 |
|
| 4 | [pron] [vb past] be necessary | 28 |
|
| 5 | it [vb past] be necessary | 13 |
|
| 6 | it [vb past] [be] necessary | 13 |
|
