| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | problems have [adv] been | 24 |
|
| 2 | problem have [adv] been | 18 |
|
| 3 | problem have [adv] been | 17 |
|
| 4 | problem has [adv] been | 14 |
|
| 5 | problem have now been | 9 |
|
| 6 | problem had [adv] been | 8 |
|
| 7 | problem have always been | 7 |
|
| 8 | problem have already been | 7 |
|
| 9 | problem have also been | 6 |
|
