| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must be something [to-vb] | 7 |
|
| 2 | it must be [pron] [to-vb] | 7 |
|
| 3 | it must be [pron] to do | 7 |
|
| 4 | it must be [indef pn] [to-vb] | 7 |
|
| 5 | it must be something [to-vb] | 7 |
|
