| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] to be [v-ing] | 5344 |
|
| 2 | [vb past] to be [v-ing] | 1684 |
|
| 3 | happen to be [v-ing] | 147 |
|
| 4 | happened to be [verb] | 121 |
|
| 5 | happened [prep] be [v-ing] | 88 |
|
| 6 | happened to [be] [v-ing] | 88 |
|
