| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult [prep] [be] [adj] | 88 |
|
| 2 | [adj] [prep] [be] sure | 88 |
|
| 3 | difficult [prep] [be] [adj] | 88 |
|
| 4 | difficult [prep] [be] sure | 30 |
|
| 5 | difficult [prep] [be] sure | 30 |
|
