| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [modal v] be difficult [prep] them | 6 |
|
| 2 | it [vb mod] be difficult [prep] them | 6 |
|
| 3 | it be [adv] difficult [prep] them | 14 |
|
| 4 | it be [adv] difficult [prep] them | 14 |
|
| 5 | it be very difficult [prep] them | 8 |
|
| 6 | it be very difficult [prep] them | 8 |
|
| 7 | it be difficult [to-vb] [prep] them | 7 |
|
| 8 | it be difficult [verb] [prep] them | 7 |
|
| 9 | it be difficult [prep] them [to-vb] | 15 |
|
| 10 | it be difficult [prep] them [verb] | 15 |
|
