| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] [modal v] [be] difficult | 44 |
|
| 2 | [Wh det] [vb mod] [be] difficult | 44 |
|
| 3 | [Wh det] [modal v] be difficult | 44 |
|
| 4 | which [modal v] [be] difficult | 44 |
|
| 5 | [Wh det] would [be] difficult | 16 |
|
| 6 | [Wh det] would [be] difficult | 16 |
|
| 7 | [Wh det] may [be] difficult | 11 |
|
| 8 | [Wh det] may [be] difficult | 11 |
|
| 9 | [Wh det] can [be] difficult | 10 |
|
| 10 | [Wh det] can [be] difficult | 10 |
|
