| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] difficult [prep] us [verb] | 24 |
|
| 2 | [pron] [be] difficult [prep] us | 19 |
|
| 3 | [pron] [be] [prep] us [verb] | 18 |
|
| 4 | [pron] [be] difficult [prep] [verb] | 7 |
|
