| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | has [been] [v-ing] a | 169 |
|
| 2 | has [been] [v-ing] on | 91 |
|
| 3 | [been] [v-ing] on a | 61 |
|
| 4 | has [been] on a | 17 |
|
