| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [subord] it is necessary | 130 |
|
| 2 | if it is necessary | 30 |
|
| 3 | where it is necessary | 27 |
|
| 4 | when it is necessary | 20 |
|
| 5 | whether it is necessary | 12 |
|
| 6 | as it is necessary | 12 |
|
| 7 | so it is necessary | 10 |
|
| 8 | because it is necessary | 8 |
|
