| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is essential for the [noun sg] | 56 |
|
| 2 | is essential to the [noun sg] | 47 |
|
| 3 | is essential [prep] the development | 5 |
|
| 4 | is essential in the [noun sg] | 5 |
|
| 5 | is essential [prep] the success | 5 |
|
