| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they happened to [be] [verb] | 8 |
|
| 2 | they happened to be [verb] | 8 |
|
| 3 | they happened to [be] [verb] | 8 |
|
| 4 | they happened to be [verb] | 8 |
|
| 5 | they happened to [be] [v-ing] | 6 |
|
