| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is not necessary [to-vb] [prep] | 14 |
|
| 2 | is not necessary [verb] [prep] | 14 |
|
| 3 | is not necessary [verb] [prep] | 14 |
|
| 4 | is not necessary [verb] to | 6 |
|
| 5 | is not necessary [verb] to | 6 |
|
