| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [be] difficult for | 109 |
|
| 2 | [modal v] [verb] [be] for | 79 |
|
| 3 | [modal v] [verb] [be] difficult | 75 |
|
| 4 | [verb] [be] difficult for | 26 |
|
