| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | has [verb] [prep] a | 2002 |
|
| 2 | has [vb pp] [prep] a | 1886 |
|
| 3 | has occurred [prep] [art] | 97 |
|
| 4 | have occurred [prep] a | 69 |
|
| 5 | [verb] occurred [prep] a | 69 |
|
| 6 | has occur [prep] a | 30 |
|
| 7 | [vb -s] occurred [prep] a | 30 |
|
| 8 | has occurred [prep] a | 30 |
|
