| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] a problem | 176 |
|
| 2 | [vb pp] a problem | 176 |
|
| 3 | got a problem | 98 |
|
| 4 | had a problem | 26 |
|
| 5 | become a problem | 9 |
|
| 6 | proved a problem | 6 |
|
