| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have difficulty | 101 |
|
| 2 | may have difficulty | 29 |
|
| 3 | would have difficulty | 29 |
|
| 4 | will have difficulty | 23 |
|
| 5 | might have difficulty | 9 |
|
