| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] [prep] [be] difficult | 13 |
|
| 2 | [be] [vb pp] [prep] [be] difficult | 13 |
|
| 3 | [was/were] [vb pp] [prep] [be] difficult | 7 |
|
| 4 | was [vb pp] [prep] [be] difficult | 5 |
|
| 5 | [vb pp] [prep] [be] [adv] difficult | 17 |
|
| 6 | [vb pp] [prep] [be] [adv] difficult | 17 |
|
| 7 | [vb pp] [prep] [be] difficult [to-vb] | 5 |
|
| 8 | [vb pp] [prep] [be] difficult [verb] | 5 |
|
