| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | this must be [vb pp] | 200 |
|
| 2 | this must be done | 29 |
|
| 3 | this must be added | 7 |
|
| 4 | this must be seen | 7 |
|
| 5 | this must be set | 6 |
|
| 6 | this must be taken | 5 |
|
| 7 | this must be achieved | 5 |
|
