| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it become [adj] | 1495 |
|
| 2 | it [verb] difficult | 89 |
|
| 3 | [pron] become difficult | 37 |
|
| 4 | [pers pn] become difficult | 37 |
|
| 5 | it become difficult | 33 |
|
