| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] is essential for | 92 |
|
| 2 | [pron] is essential for | 92 |
|
| 3 | it is essential for | 71 |
|
| 4 | [pers pn] is essential for | 71 |
|
| 5 | it is essential for | 71 |
|
| 6 | [Wh det] is essential for | 20 |
|
| 7 | which is essential for | 18 |
|
| 8 | which is essential for | 18 |
|
