| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | happened then | 62 |
|
| 2 | happens then | 56 |
|
| 3 | happen then | 29 |
|
| 4 | happened then | 12 |
|
| 5 | to happen then | 9 |
|
| 6 | happening then | 8 |
|
