| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [coord] it [be] necessary [verb] | 71 |
|
| 2 | [coord] it [be] often [verb] | 35 |
|
| 3 | it [be] often necessary [verb] | 22 |
|
| 4 | [coord] it [be] often necessary | 5 |
|
