| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] difficult [prep] [be] sure | 18 |
|
| 2 | be difficult [prep] [be] sure | 18 |
|
| 3 | [is] difficult [prep] [be] sure | 13 |
|
| 4 | [adv] difficult [prep] [be] sure | 11 |
|
| 5 | [adv] difficult [prep] [be] sure | 11 |
|
| 6 | is difficult [prep] [be] sure | 9 |
|
| 7 | [was/were] difficult [prep] [be] sure | 5 |
|
| 8 | was difficult [prep] [be] sure | 5 |
|
| 9 | difficult [prep] [be] sure [conj] | 8 |
|
| 10 | difficult [prep] [be] sure [prep] | 7 |
|
| 11 | difficult [prep] [be] sure [prep] | 7 |
|
| 12 | difficult [prep] [be] sure of | 6 |
|
| 13 | difficult [prep] [be] sure of | 6 |
|
| 14 | difficult [prep] [be] sure [pron] | 6 |
|
| 15 | difficult [prep] [be] sure [that] | 5 |
|
| 16 | difficult [prep] [be] sure that | 5 |
|
| 17 | difficult [prep] [be] sure that | 5 |
|
