| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is difficult for [pron] [to-vb] | 43 |
|
| 2 | difficult for [pron] [to-vb] [prep] | 41 |
|
| 3 | is for [pron] [to-vb] [prep] | 9 |
|
| 4 | is difficult for [pron] [prep] | 7 |
|
