| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be difficult for | 228 |
|
| 2 | it [be] difficult for | 228 |
|
| 3 | it [be] difficult for | 228 |
|
| 4 | it [is] difficult for | 169 |
|
| 5 | it is difficult for | 139 |
|
| 6 | it [was/were] difficult for | 55 |
|
| 7 | it was difficult for | 55 |
|
| 8 | it 's difficult for | 30 |
|
