| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb infin] been [v-ing] at | 15 |
|
| 2 | [vb infin] [been] [v-ing] at | 15 |
|
| 3 | [vb infin] be [v-ing] at | 15 |
|
| 4 | have [be] [v-ing] at | 14 |
|
