| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb past] [prep] [noun prp] | 818 |
|
| 2 | [vb past] [been] [prep] [noun prp] | 407 |
|
| 3 | it [vb past] [been] [prep] | 331 |
|
| 4 | it [vb past] [been] [noun prp] | 78 |
|
