| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [not/n't] been a problem | 9 |
|
| 2 | [verb] [not/n't] been a problem | 9 |
|
| 3 | [vb -s] [not/n't] been a problem | 7 |
|
| 4 | has [not/n't] been a problem | 6 |
|
| 5 | [not/n't] have been a problem | 8 |
|
| 6 | [not/n't] have been a problem | 8 |
|
| 7 | [not/n't] [vb infin] been a problem | 8 |
|
| 8 | [not/n't] [verb] been a problem | 8 |
|
