| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [not/n't] [prep] a | 1837 |
|
| 2 | been [prep] a | 1107 |
|
| 3 | [not/n't] been [prep] | 983 |
|
| 4 | [not/n't] been a | 302 |
|
