| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | should [vb infin] [verb] [conj] [art] | 65 |
|
| 2 | [modal v] [vb infin] to ensure [conj] [art] | 38 |
|
| 3 | should [vb infin] [to-vb] [conj] [art] | 20 |
|
| 4 | should [vb infin] ensure [conj] [art] | 7 |
|
| 5 | should [verb] to ensure [conj] [art] | 6 |
|
