| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had not been seen | 49 |
|
| 2 | had not be seen | 49 |
|
| 3 | had not [been] seen | 49 |
|
| 4 | had not [be] seen | 41 |
|
| 5 | had n't [be] seen | 8 |
|
