| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] has [been] [v-ing] at a | 9 |
|
| 2 | [noun sg] has [been] [v-ing] at a | 8 |
|
| 3 | has [been] [v-ing] at a [noun sg] | 7 |
|
| 4 | has [been] [v-ing] at a [noun] | 7 |
|
