| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] some concern | 8 |
|
| 2 | [verb] [been] some concern | 8 |
|
| 3 | [vb -s] [been] some concern | 6 |
|
| 4 | has [been] some concern | 5 |
|
