| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it have [be] before | 21 |
|
| 2 | it have be before | 21 |
|
| 3 | it have [been] before | 21 |
|
| 4 | it have been before | 21 |
|
| 5 | it had [be] before | 20 |
|
