| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb base] it is necessary | 24 |
|
| 2 | [vb pp] it is necessary | 11 |
|
| 3 | [vb -s] it is necessary | 10 |
|
| 4 | think it is necessary | 9 |
|
| 5 | think it is necessary | 8 |
|
| 6 | [to-vb] it is necessary | 7 |
|
| 7 | feel it is necessary | 7 |
|
| 8 | [vb infin] it is necessary | 6 |
|
