| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have played a key role | 23 |
|
| 2 | have [vb pp] a key role | 23 |
|
| 3 | have [vb pp] a key role | 23 |
|
| 4 | had [vb pp] a key role | 9 |
|
| 5 | has [vb pp] a key role | 6 |
|
| 6 | have [vb pp] a key role | 5 |
|
