| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [is] [verb] [prep] | 88780 |
|
| 2 | [is] [v-ing] [prep] | 13214 |
|
| 3 | [be] happening [prep] | 1207 |
|
| 4 | [is] happen [prep] | 693 |
|
| 5 | [is] happening [prep] | 669 |
|
