| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it was [adj] | 23603 |
|
| 2 | it [be] difficult | 2948 |
|
| 3 | it be difficult | 2948 |
|
| 4 | [pron] was difficult | 573 |
|
| 5 | it [was/were] difficult | 542 |
|
