| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it becomes [adj] | 537 |
|
| 2 | it [verb] necessary | 105 |
|
| 3 | it become necessary | 63 |
|
| 4 | it [vb -s] necessary | 52 |
|
| 5 | [pron] becomes necessary | 25 |
|
| 6 | [pers pn] becomes necessary | 24 |
|
| 7 | it becomes necessary | 24 |
|
