| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | problems [modal v] [be] [verb] | 225 |
|
| 2 | problems [modal v] [be] [vb pp] | 223 |
|
| 3 | [noun] [modal v] [be] traced | 205 |
|
| 4 | [noun pl] [modal v] [be] traced | 66 |
|
| 5 | problems [modal v] [be] trace | 5 |
|
| 6 | problem [modal v] [be] traced | 5 |
|
