| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could [coord] should | 92 |
|
| 2 | could [conj] should | 92 |
|
| 3 | could and should | 67 |
|
| 4 | could and should | 67 |
|
| 5 | could or should | 24 |
|
| 6 | could or should | 24 |
|
