| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] have occurred | 160 |
|
| 2 | which have occur | 109 |
|
| 3 | [Wh det] had occur | 59 |
|
| 4 | [Wh det] have occur | 54 |
|
| 5 | what have occur | 50 |
|
| 6 | [Wh det] has occur | 47 |
|
