| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it have been [adv] difficult | 18 |
|
| 2 | it [vb -s] been [adv] difficult | 16 |
|
| 3 | it [verb] been very difficult | 10 |
|
| 4 | it has been [adv] difficult | 9 |
|
| 5 | it 's been [adv] difficult | 7 |
|
