| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | but it [vb mod] to | 17 |
|
| 2 | but it [modal v] to | 17 |
|
| 3 | but it used to | 9 |
|
| 4 | but it used to | 9 |
|
| 5 | but it ought to | 6 |
|
| 6 | but it ought to | 6 |
|
