| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | there have [been] many attempts | 6 |
|
| 2 | [pron] have [been] many attempts | 6 |
|
| 3 | [ex0] have [been] many attempts | 6 |
|
| 4 | there have [been] many attempts | 6 |
|
| 5 | have [been] many attempts [to-vb] | 7 |
|
| 6 | have [been] many attempts [verb] | 7 |
|
