| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb -s] [be] | 7819 |
|
| 2 | it [be] necessary | 1964 |
|
| 3 | [vb -s] [be] necessary | 53 |
|
| 4 | it [vb -s] necessary | 52 |
|
