| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [verb] [been] a difficult | 17 |
|
| 2 | it have [been] a difficult | 17 |
|
| 3 | it [verb] been a difficult | 17 |
|
| 4 | it [vb -s] [been] a difficult | 11 |
|
| 5 | it 's [been] a difficult | 7 |
|
| 6 | it [vb past] [been] a difficult | 6 |
|
| 7 | it had [been] a difficult | 6 |
|
