| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | used [prep] an [noun sg] | 277 |
|
| 2 | been used [prep] [noun sg] | 139 |
|
| 3 | been [prep] an [noun sg] | 57 |
|
| 4 | been used [prep] an | 23 |
|
