| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which has [not/n't] been | 136 |
|
| 2 | which has [not/n't] [been] | 136 |
|
| 3 | which has not [been] | 124 |
|
| 4 | which has n't [been] | 12 |
|
