| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] [v-ing] for twenty year | 8 |
|
| 2 | be [v-ing] for twenty year | 8 |
|
| 3 | [been] [v-ing] for twenty year | 8 |
|
| 4 | been [v-ing] for twenty year | 8 |
|
