| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] been [v-ing] [adv] for several | 6 |
|
| 2 | [vb past] be [v-ing] [adv] for several | 6 |
|
| 3 | had be [v-ing] [adv] for several | 5 |
|
