| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [modal v] have been necessary for | 6 |
|
| 2 | [pers pn] [vb mod] have been necessary for | 6 |
|
| 3 | [pers pn] [modal v] have been necessary for | 6 |
|
| 4 | [pers pn] [modal v] have been necessary for | 6 |
|
| 5 | [pers pn] [modal v] have been necessary for | 6 |
|
