| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] be [v-ing] [prep] a | 619 |
|
| 2 | [verb] be [verb] for a | 561 |
|
| 3 | [verb] be [v-ing] for [art] | 396 |
|
| 4 | [verb] [be] [v-ing] for a | 219 |
|
