| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pers pn] is [not/n't] essential [verb] | 8 |
|
| 2 | it is [not/n't] essential [verb] | 8 |
|
| 3 | it is [not/n't] essential [verb] | 8 |
|
| 4 | [pron] is [not/n't] essential [verb] | 8 |
|
