| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] been [adj] for | 411 |
|
| 2 | [verb] been necessary for | 25 |
|
| 3 | [vb past] been necessary [prep] | 8 |
|
| 4 | [vb past] [been] necessary for | 5 |
|
| 5 | [vb past] be necessary for | 5 |
|
| 6 | [vb past] [be] necessary for | 5 |
|
