| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [Wh det] [vb base] been [verb] | 1133 |
|
| 2 | [Wh det] [vb base] been [vb pp] | 1088 |
|
| 3 | [Wh det] [verb] been introduced | 36 |
|
| 4 | [pron] [vb base] been introduced | 25 |
|
| 5 | [Wh det] [vb base] be introduced | 11 |
|
| 6 | [Wh det] [vb base] [been] introduced | 11 |
|
| 7 | [Wh det] [vb base] [be] introduced | 11 |
|
| 8 | [Wh det] [vb base] been introduce | 11 |
|
