| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] be [v-ing] | 5654 |
|
| 2 | [vb past] [prep] be [v-ing] | 1697 |
|
| 3 | happen [prep] be [v-ing] | 147 |
|
| 4 | happened [prep] be [verb] | 121 |
|
| 5 | happened [prep] [be] [v-ing] | 88 |
|
