| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [v-ing] [prep] a [noun] [conj] | 365 |
|
| 2 | [am/are] [v-ing] [prep] [art] [noun] [conj] | 347 |
|
| 3 | [am/are] [verb] [prep] a [noun] [conj] | 274 |
|
