| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] it [prep] [pron] [to-vb] | 70 |
|
| 2 | it difficult [prep] [pron] [to-vb] | 65 |
|
| 3 | [vb past] it difficult [prep] [pron] | 29 |
|
