| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] used to [be] | 1772 |
|
| 2 | [Wh det] used to [be] | 208 |
|
| 3 | what [modal v] to [be] | 186 |
|
| 4 | what used [prep] [be] | 139 |
|
| 5 | what used to [be] | 139 |
|
